I feel like when people downplay this idea they are assuming it has to be like Dawn of war which was heavily squad based like the table top game. In the fluff though though I think a modern total war game could pull it off. Multiple planets and sections you could take over - so much room for customization and tactical options.
It wouldn't need some advanced cover system, they already have terrain effects in place like wading through water or forests. I am sure modifiers could be used to make a workable cover system.
The only feature I think the engine would need is destructible environments (which are due for total war by now).
The total war engine is getting more and more powerful as time goes on IMO.
Sorry noob poster, used to be a big DoW modder though years ago