Yeah, I mean even if you base Lyn off Ike you still need to redo a ton of those animations. Like I was saying before, there's no way she can just retain his fsmash and that makes any kind of sense.
I also do like the idea of her having the bow. Maybe it wasn't a part of the character everyone saw, but I think that's okay considering some characters don't even use their own moves. It also gives her another interesting point of distinction. Marth is a pure swordsman, Roy is swords + fire, Ike is a really brolic swordsman, and then Lyn is a nimble swordswoman (lol) with a bow. That's kind of a cool angle, and even though it's not the best representation of all the different FE classes, it does paint a sort of picture, haha.
There are also a few Sheik attacks that would fit pretty well. I could totally see nair staying the same, for example, and even bair/uair. I like the idea of Lyn as this character that uses her sword less frequently than the other characters, and kind of only when it's going to be very powerful (smash attacks and specials, for example).
I dunno. If she's based off Ike, which animations do you think you can retain? Certainly not the smash attacks. I'm thinking bair and the tilts, and that's really it. (and probably not uptilt, that's too meaty).
Again, I have no problem with her being based off Ike. I like both those ideas. I just don't think it's as clear cut as basing her off Ike saving tons of time. I think it saves you two-three moves, tops, and you lose out on an interesting option by being unable to ever give her a bow.
edit: lots of posts came in while I wrote this, I was talking to the tomato : >