It does break the pattern, but Li Long is nevertheless the best fit by far, if not exactly as much a one-for-one match. He is the only character who uses his yells as his intro dialogue, and he's quite vocal in that respect in a fight as well. It would also mean that each of the characters selected for the final six were exactly those six needed to complete the main cast from those exact four games which have contributed characters so far (SE, SCI, SCII, SCIII). Attempts to foist Hilde into that role (because she supposedly yells here dialogue; which of course she doesn't to any extent beyond that of the average character in this franchise) are just wishful thinking/confirmation bias/pipe dreams on the part of fans who aren't willing the look at the pattern established here, the clear indications from the development team about their priorities, or the rest of the body of evidence. Neither Hilde nor Algol are making it into this cut--I feel pretty confident about that. I hope we may yet see a season 3 where they do, but they are almost certainly not a part of The Six. Li long is the only option that fits the contextual information we do have and at least has a strong possible association with the "Yell" codename.
You do raise an interesting question, though; I don't now why they didn't go with 'DRAGON'. Perhaps because of the possibility of confusion with Aeon as he appears in SCV? In any event, I'll say it again, though I know the next three pages will be filled with yet more speculation about Hilde, Algol, Viola, ZWEI, and even Dampierre, from those who either don't read more than a page back into the thread or just want to keep on convincing themselves that there are reasons their favourite choice will prevail against all evidence: Reptile=Lizardman, Star=Yun-Seong, Yellow=Hwang, Stone=Rock, Snow=Setsuka, and Yell=Li Long. Classic roster, here we come!
Yuuuup. And its not exactly something new to this franchise. Same exact sorts of comments, in some cases almost word for word, have been said about at least one guest character in every game that has included them. People are already adjusting though, as they always do; complaints in this area were constant the first two weeks (as is predicable when people are getting their asses handed to them as a consequence of not being able to get a read on a style that is foreign to their experience), but they have quieted mostly to a murmur now. She's also been nerfed a bit (a little too hard, actually, imo) and that has helped.