@xiix: Thor, while falling from the sky, with Mjolnir in hand, couldn't make him bleed. A point blank blast from SS couldn't make him bleed. Odin didn't make him bleed. But Namor, who couldn't KO Tchalla, put Thanos on his knees and made him bleed? I didn't say it was PIS. Just a low showing
Making characters bleed is WAY overrated on this forum. You know what makes some characters bleed a lot? Artists. Some love having blood everywhere. This was a common complaint in Duggan's run of Hulk, that Hulk whose been through all sorts of epic damage not bleeding was bleeding on every gamma-powered hero he was turning. The artist loves showing blood, and that's why.
The example that always comes to mind with bleeding vs damage is a friend of mine growing up. A needle to his arm, makes him bleed. He also fell from a tree cracked a branch in two with his head, nearly blacked out, puked and was dazy for hours, but never bled. So according to some, the needle was more damaging than the branch to the head...
Lastly Namor is a legit power-house, he through everything he had into that punch, breaking every bone in his hand, I don't think it's that unreasonable his sucker punch made Thanos bleed.