I'd just roll with the Astr*s real roster, but to keep things fresh, maybe consider each series against whichever opponent, make changes to how you play. for instance, in Ho*ston's first series against the Angels just play that series every pitch and every at bat. then moving on to the Oakland series, play with quick counts on. the third series you could do something like pitch only. the next series maybe bat only. the next series play only the first 3 innings of each game and sim the other six. next series play only the middle 3 innings and sim the first and last 3 innings. next series sim the first 6 innings and play the last 3. next series maybe play everything like you normally would except try using a different pitching mechanism, like if you're a meter guy try using pulse. I also like to occasionally tinker with my batting lineup. maybe when you're on the road at an NL team bat your pitcher 8th. I also like to rotate through 3 very different slider sets, 1 default, 1 tilted to pitching for both human and CPU and a 3rd tilted to batting for both human and CPU. there is really no limit to the little things you can change up slightly to keep it fresh. for instance I also like to rotate through the 3 ump settings, perfect, average and personalised