We still haven't seen masses of Cormier at LHW but we've now seen enough to know the cut isn't a problem for him which was the big unknown before. Now that's clear his performances at HW are obviously tell us a lot about his LHW potential.
Hendo for me shows the difference very well, Rashad just about took a decision vs Dan based on picking away from distance, Cormier took him down and dominated him on the ground.
Cormier might have trouble with Jones reach but I think you also need to consider how wrestling effects standup. A lot of the way Jones uses his reach is via using the threat if his wrestling and the clinch rather than via a jab or power straights, when guys look to close in and exchange with him he tends to switch straight into the clinch. If Cormier has the superior wrestling and wants the clinch that changes the makeup of the match a lot and even if Jones avoids the takedown it could be a lot easier for DC to get close to him and exchange, an area where I think Jones defence whilst improved is still questionable.