As for losing Maiming and Scouting gear.
IF they dont add any more melee jobs, then you might be right about Maiming gear. However having too many jobs sharing the same gear is going to make having multiple jobs with different builds very tricky to manage.
Same goes for Scouting if they dont add any more jobs that use Dex.

But as future melee and ranged jobs ARE likely, as I indicated in the OP, merging them would end up causing problems. They need to expand them instead.