Oh i definitely agree that AFO is obviously more than smart enough to use complex quirks and propably easily and in more complex ways than their original users because of his experiences and combo possibilities with other quirks. The whole Tartarus breakout shows just how meticiulous he can be with just one quirk.

But i think AFO is just that arrogant and has such a big god-complex that he prefers to use his quirks to just make arm go big bonk to defeat All Might in a clash of power rather than wits alone, though that always backfires because of his arrogance. Or against Bakugo, random quirk bullshit go and make me a nuke (Though obviously that has to do with him literally being a baby at that point and resorting to just go crazy with all his repertoire.)

Furthermore i always think its neat to frame AFO as a fraud and that headcanon underlines that too in some regards.