how do you know they needed Roger to step in, the Marines have an entire army aside from Garp who werent there, not to mention Sengoku and Kong, and at least 2 other admirals
All of that wouldn’t have been enough if roger decided to team up with rocks. But even with that not being the case odds are against the marines.
The reason the event wasn’t more publicized was because the greatest pirate to ever live decided to help out.
also we can’t assume there’s two other admirals or if they are as strong as sengoku and garp, the leading marines at the time were sengoku and garp and Kong was the fleet admiral. also Sengoku is a shiki level character it’s not going to turn the tides of this battle. Sengoku + Kong is not equivalent of roger plus crew also btw. Also we do not know if all the allies of BM, WB, shiki and others were present. Armies don’t mean as much anyways with so many Conq users. You seem to be taking a marine centric viewpoint here.
Even the government realized they don’t have enough manpower and recruited the warlords to achieve a balance in power, of course until now due to some scientific breakthrough etc.
The details of this fight is unclear roger’s crew probably helped out etc. which could explain how the others were kept in check since roger’s crew is OP. but the fact of the matter is it cemented the already great Garp as the strongest marine to date.
the pirates have more legendary characters so far. Only Garp can be put into that tier so far from the marines.