I dunno, I feel like the threat posed by the gifters has been well-established. We've seen even the likes of Zoro and Yamato struggle a bit with them, and they're strong enough to fight Kaido, and it's reinforced this chapter. It's true that their threat comes more from their numbers than their individual powers, but that's how it was established all the way back at Zou, so it makes sense for the way to deal with them to be based on numbers.
The implication here is that the gifters are big enough of a deal that the alliance would have probably been defeated without Tama's intervention, which is why we've spent so much time with her and this gets so much focus now. It's a major turning of the tides moment and major feat for Tama herself.
Although there has been a lot of tell,don't show in Onigashima so far with the danger, tbh. This applies now when we found out the gifters are a problem for Jinbe, Franky, Inu, etc just before Tama turns things around. But also in things like when we moved away from the rooftop fight and when we went back you had Kid and Law being all like ''Holy shit these guys are insane, you can't even call them human, this is worse than being in hell, just surviving this long is a miracle, we're struggling real hard I swear'' but then both before and after that they seem to be doing just fine.