then thats good news altho i doubt they fixed Rome Total War, since it had flicker as far back on multi gpu since the 3800 series. Nvidia isnt much better, anything from the 8000 series - 400 series couldnt run Shogun or Medieval 1, for about 10 driver releases the 580 would give a black screen on Empire, altho those issues have been fixed since. GPUs + Total war is a crap shoot roll the dice you get what you get.
CPU side tho nothing AMD has even compares to Intel sadly, I do agree A10 is the better choice all around but if Total war is the OPs thing going AMD is just a waste of time and money on the CPU side.
AMDs best chips pushed to 5ghz still cant beat stock low end I5 chips. But again thats a developer choice Intel did the grunt work for the supposed multi-threading which is to say they did nothing at all
I do know that Rome and earlier are pretty much broken mess with multi gpu, but its to be expected really games were never programmed with it in mind, hell I do believe Napoleon was the first one to start scaling properly on most hardware configs, with Shogun 2 doing rather well when not limited by the CPU which is nearly every battle once melee is joined. Mostly because of a limitation in the game engine.
Warscape = gunpowder Empire + Napoleon = gunpowder all is well
Shogun 2 = Warscape and is 90% melee, engine was coded effectively for that. Using 1 core to handle both physics / animation / ai the game has these things interconnected to such an extent that AMD cant bring its multi-threading or multiple cores into the equation. that said a 6670 with a few settings tweaks, + an Intel chip can run the game just fine if said 6670 is the GDDR5 version, if its DDR3 not so much. Games also a memory bandwidth hog.
Bit thing is keeping settings withing the memory budget, as the game likes to auto scale down graphics settings if it runs out of vram which is why at launch the GTX 580 was winning against AMDs cards. that said 2gb is a large enough frame buffer to max graphics settings at 1080p gpu itself tho would need a 7790 overclocked minimum, which with further tweaks should run mix of High / Very high fairly well.
Really tho depend on the OPs location I know newegg has a deal for 8gb of DDR3 + 7850 2gb where the memory is pretty much just $15. but it also depends on if the OP was looking at prebuild rigs as well. I know the rig I just built for a customer was $888 up front after rebates got it down to $840 ish Dell / HP were around $1200 for the same specs.
Anyway I am rambling for Total War games like Shogun 2 he needs Intel CPU hands down preferably Ivy Bridge i5 even if its the lowest end i5 chip it will still be faster than all other options.
For older total wars he wont need much to max them out.