I think Katakuri's AP is G3ish for the most part with some attacks being stronger.
But I disagree about Prime Garp though. I've read the scaling for it and I disagree, Garp's punch overpowered Prime Chinjao's head when it was in its drill form. Luffy did it to a Old Chinjao and a blunt drill.
I think prime Garp can hit way harder than that.