Thought I'd just make my own topic on this rather than respond to the countless comments on the forums complaining about the removal of cover/synch kills in DoWIII. Many of these people express fondness for DoW2/CoH mechanics, and wish for these core features to remain in the game (hey - at least it's a better complaint than "MOBA MOBA MOBA.").
I disagree. After analyzing the costs/benefits of these features on their impact in-game, it's clear that **the removal of cover and synch kills was a good move on Relic's part. **
DoW3 made a good decision by removing these features. It will help promote smooth gameplay. What do I mean by this? Cover/synch kills has always been more of a problem than it was worth as a "feature" in DoW2 in my expert opinion:
1.) Cover was not worthwhile - Often times battles would usually be decided in a matter of seconds (DoW2 could be very fast paced), as the choice between attacking immediately or spending an extra few seconds to get behind cover usually meant it was inefficient to seek cover unless immediately available. This is not to say that cover was useless, but that it was not an important part of victory. For example - say your tact squad wanted to seek cover vs. a ranged squad (Guardians, say). They could duke it out with mutliple squads this way. However, they are also not dealing a lot of damage in return. This means that cover-to-cover battles would take an exceptionally long time to resolve in the scale of DoW2. As such, it was common to simply outflank cover to move a heavy-weapons team to suppress the target in cover (winning the fight). What does this mean? It means that staying in cover was the losing strategy. You had to constantly be mobile and on the move to gain the tactical edge in positioning.
-Cover does not work like this in CoH - units take a much longer time to resolve combat (even out of cover) and the basic damage mechanics lends itself better with the cover system. The problems above are just for DoW2.
2.) Cover caused many, many bugs - That's right, this is the main reason why I'm not sad to see this feature go. On top of the already low-impact cover had on competitive games, it was the cause of many retreat, pathing, and terrain bugs present throughout DoW2's history: units getting stuck in cover, getting stuck on terrain in retreat, clipping of abilities, unpredictable pathing, etc. These all were tied to the game's core engine and code used to make action in DoW2 interact with cover and terrain.
3.) Squad behavior - Small squads, like eldar, CSM, and Space Marines, didn't have much problems making use of cover as each model could be placed in cover with ease. However, larger squads, like orks, imperial guard, and especially tyranids, have always had a difficult time making good use of cover. This is because that only half the squad's models would actually be in cover while other half stands outside (having them take full damage from incoming fire). This fact made cover even less relevant in competitive play. All it would take it 1-2 models wandering out of cover to get shot down and you would already have lost the fight (even the aforementioned Space Marines would sometimes wander out of cover).
4.) Synch Kills killed competition - One of the signature features of DoW series and one that I'm a little more sorry to see go. However, synch kills presented numerous competitive challenges in DoW2 (and to a lesser extent, DoW1). Sure, the animations were fun to look at, but after your 1000th+ game, they're nothing special to look at. Synch kills would end up being a major balance concern (and rightfully so) since when a squad entered a synch kill, they had to finish it before they could do anything else. It was possible to activate a retreat from a synch kill, but they would still remain in that spot until done (while receiving extra melee damage, reduced ranged, and building speed). Sometimes the synch kill wouldn't matter at all (say, a simple 1v1 fight - even a bit beneficial since the enemy squad members will be whacking away at the synch kill member doing negligible damage). Other times, synch kills would literally win(or lose) you the game. For example, a banshee squad might start a synch kill vs an ork slugga squad after a bit of a melee (meaning they have less than full HP). In DoW2, every second counts and a late retreat could easily mean a dead squad. So if this banshee squad starts a synch kill while the enemy's reinforcements are coming into view, setting up a flank, or charging in - there's nothing you could do to avoid it. You had to watch the squad member finish the synch kill while the other members stand around like a sack of potatoes before you could escape. It was not uncommon to see a squad wipe from a synch kill, that activated for no other reason than pure chance.
-It removes player agency by taking control away from the player - potentially causing a lo of balance concerns as I described above. This is not something you want for competitive games (in 1v1, 2v2, or 3v3) as the players feel cheated by the game.
Relic even patched-out synch kills from DoW2: Retribution for this very reason.
5.) Removed/patched out "auto-cover" - another advertised feature of DoW2. While it looked cool and added immersion with lifelike animations, it took away unit responsiveness just like Synch-kills. This could most notable be seen with anti-vech infantry (e.g. a missile launch tactical would run around trying to seek cover, despite being in range of the vehicle and receiving an attack order). In a game where every second of combat counts, having a unit derp-out for a few of those seconds was less than ideal, to say the least. I know I was robbed of quite a few wraithlord kills because my marines would refuse to fire and instead run up towards shuricannon fire or a banshee squad instead of just f-ing fire.
So, the removal of Synch kills and dynamic cover is not such a bad thing. In fact, I applaud the decision. All you have to do is take a look at the gameplay footage coming out to see how well the game runs (units behaving normally, good pathing, responsive - a lot like Starcraft, as I noted in the past - which is a really good move to promote competitive RTS). DoW2's release was plagued by a plethora of concerns (balance, bugs, and multiplayer functionality) due to the complexity of mechanics and a rushed release (it took a couple years to balance the game to a stable state).
Superficially, I can see how the removal of "features" can seem like a dumbing-down of DoW, but these features are actually not as good as you would think/remember. I see Relic's "simplification" of DoW3 as a means for them to focus on nailing smooth gameplay - which they seem to be accomplishing well. Basically, I'd rather have a functional game at release than one with bugs/coding issues.
I think a lot of people are looking back on previous DoW games with heavily rose-tinted glasses and therefore miss the massive improvements Relic has already made to the series.
TL;DR - So for everyone out there who is upset that these features are no longer in the game - don't be. The new approach taken by Relic will not only be better from a technical standpoint, but also encourage plenty of new strategies (found in dow1 and SC) by virtue of their tight gameplay. The removal of Cover/Synch kills will translate into smoother gameplay as well as encourage a more competitive meta with its more "classic" RTS mechanics. I think this decision was fundamental in making a tight gameplay experience (essential for multiplayer health and esports) - now we will have a lot less players complaining about game functionality and more about balance.