So I play Orc top 10 and there is no counter for Space Marine t1 spam on this level. Not with endless value Killteam.
But from the start: There are 2 Sm builts, ASM spam and tactical spam with multiple doctrines, both followed up by lasscanons into dreadnought drop on core structures.
ASM spam works the like following: Pressure Shield Nr.1 with first two ASM-squads from the start. As soon as the orc player reacts, sent ASM-drop to the second sheild + killteam on minute 4. In between your pushes, snipe the req/power-gens (this is special lame on morks mire where the orc has to move around the hill). If orc built a LP, he doesnt have enough army to fight you back. If he doesnt built a LP, kill the gens. As soon as Killteam is availabe, shieldgens' shields dont protect Orc anymore, he has to push out into SM (and die) or retreat due to flamer (rocket luncher does as well). ASMs can't be killed if the SM isn't braindead, 2 jumps means a free engage and a free escape. Orc has ZERO mapcontrol at this point, if he goes out on the map he dies. The resources you gain from killing the shields pushes the game into fast lategame (dreadnoughts) and fast elites. Its an unstoppable lame train if played right.
Tactical spam works the same, the difference is that you have even more map control, but you have to wait for killteam to kill the shields instead of pushing right away.
The key to laming the opponent down is clearly killteam. Not only does it grant you early flamers vs infantry/cover or rocket luncher vs structures/vehicles, it also comes anywhere on the map with shield and the ability to call home to gain full health regen. This allows the SM to push, and then defend the counter play right away, without risk. Not to mention the ability to summon later elites around the Killteam.
To see how strong it is, compare it to the 2 point elite of orcs. Literally a bad Orc-ASM-Squad (1 jump as elite while ASM have 2, lol) with 2000 normal health and the ability to cast an almost useless suicide boy for the cost of 1/4 of their hp. 1 doctrine is useless, the other one gives you an lame skillshot that got nerfed so hard it is not worth playing anymore. AMAZING VALUE. Compare it!
Apart of that, ASMs are still a too strong pushing power. 1 Squad can put down any structure if not defended. Same for Tacticals with multiple doctrines. By the time the SM has 5 squads with grenades, the orc gets his first shooter boys scrap (1 grenade vs 5, gj on the balance there). As soon as you lose a fight as Orc (which is hard to avoid), SM guns you down while chasing you due to "fire on move". What has the orc in return? Betta shout + thumb from the sky? Useless.
So you once complained about no one using lategame elites - thats why. There is no lategame. Orcs get strong on minute 20, when they can construct vehicles out of scrap and have enough resources to use towers as an situational pushing tool. But you never reach that point (vs good players). Thats the whole strategy on this exploits. Missing the 2 point elite as Orc (and getting a 3 point instead) is equal to give away a shieldgen for free which gets the train rolling.