Is it even viable at all? So should I just always pick her AAA?
Monkeys assist is pretty wild. I’ve dribbled a little knowledge about it over the years, you can find some of it if you search for any of the low tier threads from 06-07 probably, but what it boils down to is, plain and simple, there isn’t another assist like it in the game for a couple key reasons:
its SLOWWW. AFAIK its the slowest moving projectile you can drop on somebody. Seems like a novelty at first, but the sheer fact that it creeps along the screen means you can use it to set up extended combos, block-strings, use it as a shield by wave-dashing around it. Also, it moves so slowly that you can often recall the assist to set up double and even triple threat Monkeys depending on what action the opponent takes.
its a multi-part projectile. All this means is that it can trade with other assists or normals and still leave a couple monks floating around.
its Screen-shift/Flying Screen resistant. There’s a handful of assists that for whatever reason are resistant to flying screen, meaning, if the screen locks onto you after FS, your projectile will remain an active hitbox off-screen and not disappear when the screen resets.
Now a basic way to turn Monkeys from a random novelty into an exploit is to work with something like Launcher+Monkey assist, air combo, and end with a HP/HK finisher that grounds them just as the Monkeys roll up. This creates am Okizeme/Wake-up scenario in which they MUST block you one way as you recall an assist and pick your new attack angle.
This strategy can give lows an aggressive Rush/Lockdown approach once you get a hit. IMO the best characters to make use of this are the ones that can apply lockdown pressure solo from mid-range to far-mid.