So as in, he is still on Roger/WB/Yonko's overall level, but isn't drastically above/below them, but gets them to think he is, using cunning?
It could work. Honestly if Shiki is anything to go by, two tiers can still struggle somewhat to beat one even if they are comparable in strength.
So we can still have Garp and Roger vs Rocks without Rocks breaking the powerscale.