You mean half of the grandline? I dont think that you can group yonkous as one group. Just cant.
I think that globaly marines are strongest group. They fight RA, scores of other unafiliated pirate crews, yonkous at the same time, they have resources such as vegapunk, Pacifistas, CP-# units and who really knows what else.
if all 4 Yonkou join force they can be strongest group around because if u talk about groups they said balance 3 group to run one piece world smoothly r WG/marines , Shichibukai and yonkou .
this balance is WG/marines + Shichibukai = yonkou
if u think some differently u will find group r like
WG/marines official good people (we know truth how good they r)
Shichibukai pirates but marines dont do anything against them if its not necessary
Revolutionary Army enemy of WG
yonkou powerful pirates (other pirates can join them)
there r pirates (luffy , kid , law etc) u cant forget about them so if u want total every power u have to add pirates in yonkou and . because u cant add all pirates in marines and Shichibukai's maximum number is 7 even if u change Shichibukai then u remove one powerful pirate from that group and add them in yonkou group
so if u take that yonkou r most powerful group
Gonna go with the Yonkou here seeing what Whitebeard did to Marineford.
For all that though, he still lost. Newgate himself was killed, the Marine and Shichibukai won the war.
That's only one of them. Still 3 of them remaining, who haven't even fought. If they were all allied and attacked together, Marineford would have been destroyed completely. Granted, if they were up against all Yonkou they would probably have a greater force waiting, but let's be real, most of their fighting power was already there. It's a good thing (for WG) that there is no Pirate King (yet). Only someone like that could unite all pirates.
As for Revolutionaries, it pays out more to make the people turn against WG and their kings and subsequently join their army, than to attack kingdoms and kill potential allies. If I remember correctly, Ivankow said he was waiting for the right time to get out of jail and join the fights. There are probably others who are waiting and, in the meantime, their army is probably getting bigger and bigger.
It depends on how you define group. For me, the Yonkou are definitely not a group, it is just a term for the 4 strongest pirates who own territories in the NW. If Yonkou are a group, then so are pirates in general. Marines and the WG are the strongest "group". The problem in the "Great Pirate Era" is not only that very powerful figures have appeared but the sheer amount of pirates in general.
Well the thread made them into groups and out of all these, Yonkou seem to have the greatest military might. Not all pirates are part of Yonkou alliances.
Well, the issue here is that the yonko aren't an unified force, they are simply a group of powerful pirates with strong allies. Each of the yonko has as an enemy at least the yonko that border in their territorries and the world government. The world government has as an enemy basically the 4 yonko and every pirate in the world. The world government has to protect the entire first half of the grand line, the 4 blues and has to fight the constant chaos of the new world. At an individual level I would argue the strongest single organization has to be the marines given the sheer scale of what they do on a daily basis. The marines seem roughly even with WB's forces however if that truly where all of their assets then the world would have been left unprotected for at least the duration of the war. The marines basically are strong enough to fight on par with all of the WB pirates and keep the world at peace to some degree. The marines would likely get obliterated if the yonko worked together however that is not a likely or even plausible scenario. As far as we know the marines being supported by the government (all the governments in fact) are likely the largest and best funded of all powers.
Anyway, I think the Yonkou are the strongest. If I understood right, the Marine and shichibukai exist to fight the Yonkou, and Whitebeard himself in his old age was enough to stand up to the Marines and shichibukai. Shichibukai actually exist to deter other pirates from being too unruly, and the fact that they get recruited shows the power they have, whether it's the power of individual (Crocodile) or power of the crew (Buggy).
Seven warlords of the sea and 3 admirals and their crew/army against four emperors. Says quite a lot IMO.