I’ve thought subs and sea creatures could both be faster on average. Though I’d much rather increase a few base moves than have Mercenary helmsmen give +L. I think that would open a can of worms with power gaming – San Cristobal with SS Tsai could go S+S+L+L, as fast as the Hai Peng. Not to mention 10 masters flying all over the board at comical rates of speed.
I think some of the Ex-Patriot crew just didn’t have great abilities/costs to begin with. Between being “clones” of previous crew and the cost of Ex-Patriot, they really need something special to be worth using often. (Nemo, SS Tsai, etc)
I think they messed up relative speeds with the reverse power creep. A lot of the 1 masted ships post-DJC could have their base moves doubled without a change in point cost. Having the San Cristobal one of the fastest ships in the game while the Stingray and other RotF/F&S sloops move S or L is laughable.