I did look at the m’s — and you are wrong. The basic stroke lengths and arcs are the same in all five cases.
If you want to see examples of truly different sigs — see the twins.
It’s possible that the purported Obama record is actually signed by three different people. Just not likely on the basis of the high similarity between the THREE signatures.
On thing that gives me pause is that I’d think even a half-decent forger could forge sigs better.