Ok. maybe Ultear is 4th but way below those three(assuming of course that the new girls are actually equal to Erza, cuz you never know...)
-Laxus: But I never tried to prove that Laxus was weak ^^. You said:"..does it mean that Natsu is stronger than Laxus.." implying that Laxus' defeat was the same as Ultear's. It isn't. Letting your guard down in 1vs1 is not a "cheat"(be it flashbacks or whatever). Also, when you mentioned that scene with Laxus you said
-Shuda- said:
I remember both Natsu and Gajeel being paralysed on the floor after the Lightning Dragon's Roar, then Laxus cast Fairy Law. (Then ensue plot/character induced scenario)
which sounded a little bit like you ignored the fact that Gazeel took that lightning Lance spell in the face for Natsu, which for me stands as basis to tell you "2v1 all the way" which in turn provides me with enough evidence so as to tell you that in no way is Natsu superior to Laxus(putting DF aside) and therefore your example was irrelevant to this talk about Ultear(hopefully we made this one clear at least).
Also, Hades beat in a fair 1v1 Makarov who is viewed as the most powerful of the 10 that we have seen so far(though we can't speak conclusively about Jellal), so Hades might as well be considered the strongest we have seen so far in action (reminding you here that we have yet to see Zeref in actual action). It's not that numbers didn't matter, it's just that Hades needed more numbers against him to compare him to Laxus' past situation. If it wasn't for the fact that it was 4v1 then Hades would just have killed them one by one, no sweat.
Edit: FT made clear that those 7 years don't matter >_>. General feats don't matter. Battles and their results do. By that logic Sting is STILL superior to Natsu since he killed a dragon (assuming that it is true)