Well, Sora was able to defeat Xemnas one on one, while Terra wasn't able to defeat Xehanort. Assuming Xemnas is just as strong, or stronger, take that for what it's worth.
I can't exactly say if Sora is as strong as them or not, but he certainly has grown a lot with his power. The enemies Sora has defeated are pretty much as strong as the enemies Terra, Aqua, and Ven have defeated. Ven is obviously the weakest of the trio, and Aqua's probably the strongest. I wouldn't be surprized if he at least met Ven's standards.
I suppose the main edge TAV have over Sora is the armor. I wouldn't be surprized if their armor is stronger than Yen Sid's clothes which provide more power yet little defense. Sora's mastery of the keyblade also isn't as high as TAV can also use their keyblade has vehicles.
Either way, if Sora isn't as strong, he certainly isn't far below.
skyfoxx said:
1. 90% of Sora's fights were with his friends. TAV were all alone in their fights and usually were triumphant. Sora always needed his buddies to kill stuff. People say "Oh, Sora killed Xehanort's Heartless and Xemnas!" No... Sora, Donald and Goofy killed Xehanort's Heartless and Sora, Donald, Goofy, Riku and Mickey killed Xemnas :/
2. Drive forms are an example of him using the power of his friends. TAV have something better called "Style change" which is purely their own ability, unlike Sora's.
3. Sora doesn't know how to use his keyblade as a vehicle, can't use it as a canon nor a whip, Sora doesn't know how to make an entire castle transform, and if you actually look at the abilities that TAV use, they're 10 times more powerful than anything Sora has done in the past.
1. Sora defeated Xemnas 1v1. However he had help from his friends defeating a power up Xemnas. He also was able to defeat a dual-wielding Roxas, and Roxas was only second to Xemnas in the Organization.
2. Two things are wrong. We can't say exactly how canon those are, but assuming they are, we certainly can't say one is better than the other. If we're going to rely on gameplay alone, then TAV's forms have nothing on Sora's Final Form. Let alone he has two drives that don't require the use of friends.
3. It's true TAV have better mastery over the Keyblade than Sora; unsure if the type of keyblades they use have anything to do with it. Still, having a stronger weapon doesn't not directly link to a stronger person.