Framedata is alot more than finding 5A's and unsafe stuff. Frametraps, links for combos, gaps in blockstrings, recovery frames for whiffed, but still safe moves, are all important. And sometimes the quickest move is also the shortest, so it may not punish properly spaced moves.
Counter Assault is a guard cancel, and won't save you of many things. Not to mention you can't use it on moves that are safe on block for the opponent, and you can only know this precisely through framedata.