Honestly, the biggest part of this how Crocodile has been portrayed thus far, especially at Marineford. If Oda wanted him to be a comparative weakling, he sure as hell wouldn't have had him clash with Doflamingo, one of the strongest Shichibukai (second to Mihawk imo), and Mihawk himself, without completely getting his ass handed to him. When Oda wants a character to seem weak, he shows it - Moriah getting smacked around by Jinbe, Buggy's obvious weakness during the battle, etc. - and he certainly didn't show Crocodile as weak.