I need to get some splash damage out (storm, disruptors, colossus), but I don't know what to go for in different situations. How do I know which one to go for against Marine/Marauder or Roach/Ravager/Hydra?
I know this question might seem kind of vague, so if I can narrow it down in any way, please let me know. I'd appreciate any help.
Also, would sentries help in these situations?