I just tried you're method, which is something similar to what I did, and it failed.

When you do my left, each arrow tap, it moves his arms like hes walking, and when you hold it, it shows him walking. Do that way above and every other form of it I tried, only shows him move his right arm then stop. It also happens so fast that it doesn't look natural.

Like I said, for what we need right now, the method I did doesn't exactly look the best, but it works. Its not a huge amount of complexity or extra lines for an even noticeable difference.

Over this sprint, I'll be working on a better approach, but for mean time, my way is the only way I know of that works.