I'd rather see the cross-class system fleshed out rather than closed down, but that's only because I actually want some fair semblance of progressive player identity, realistic inter-connectivity, and customization.

For instance, each class may come equipped with x number of core mechanical traits (rather than merely ability enhancements, added output percentiles, or added stats) and y number of trait slots which only slightly exceed that x number, and all but a few of which can be filled instead by traits from other classes. Want a speedy Pugilist with a Lancer's use of Momentum, or a Lancer with a Rogue's natural mobility? So be it.