Although, DoW3 attempted to hearken back to dow1 with base building, one thing that really sticks out like a sore thumb to me is the continued inclusion of "tiers" from dow2.
One thing I liked about dow1 was the organic and unique feeling of each factions tech tree. For example, for eldar to unlock their big toys, they had to research "annihilate the enemy" at the soul shrine.
Tiers on the other hand, feel a uninspired and shallow, and they serve to homogenize the factions. In fact, the way orkz tech in this game is by far the best, because it is unique.
If a future expansion is done, it would be nice to see some depth added to the tech trees, and for each faction to have a unique way of teching going forward.