For me it's kinda hard to assume that Drake and Apoo have better showings than Izo for now
The boss was clearly overpowered during the fight, and his partner got defeated alongside Izo himself
Even if Drake comes and defeats the boss Izo will still be looking arguably stronger
Unless he shows some crazy abilities that we had no clue about, could even be a Devil Fruit, so if Drake beats him i think it will be a good feat
But still, Izo just looked awesome as hell, he was so injured but still fought 2 at the same time and beat 1 of them.
But thinking about it now... Oda could be actually be tricking us, like, Izo could've simply done something to the boss to take him out of the fight momentarily, Izo knew he was the stronger one (that would explain why he is sitting on the ground), then Izo just took the opportunity to defeat the other one even if it was going to cost his defeat.
This fits what he says about Kiku "being safe", he already knew it was going to be his last move.
Meaning that the CP-0 boss still has more to show (as i said above)
I think Oda wants to give a huge W for Drake to make him look even better than Izo by beating the CP-0 boss, that might show his true strength. Drake also looks too hurt