YFull and FTDNA create their trees largely independent from each other and if YFull has so far no members of the respective branches in its tree, they don't create them. FTDNA has generally more testers and more branches, though there are here and there exceptions with YFull having more. You will also note that they name the branches differently, just like they detect them. So the same branch on FTDNA might be named after a different significant SNP than on YFull, even if its, actually, the same branch both describing. Just think of it as two researchers and each one getting their own material and sorting it their own way, based on just some rough preliminary outline which was established by others before. They are both pioneering without watching each other carefully, which can be quite confusing at times.
My branches and subbranches have different names on both sites as well.
