I am not worried in the slightest, his only competition is Impa and we have another Robin situation. Let us be honest, Impa is more prominent (like Chrom); however, his decision to keep Sheik and add Greninja detracts from what Impa offers unless he wants to use her Hyrule Warrior's variant (I would not even be mad). Ghirahim on the other hand, he writes himself!
Getting worried about Ghirahim though, especially if we get a whole week of disconfirmations...