You know, the more I look at it, the more this is a great way to subtly emphasize skills. Want lots of high power combat, make more weapon groupings. Want everyone to be a spec-ops soldier, come up with an appropriate skill group. The lower cost will encourage people to take any group that has two skills they would have taken anyway. So the support skills are more or less free. That was actually the idea behind the Sarariman joke group. Its four skills that just about everyone should have a level or two in. Just be careful to avoid overlapping skills that already exist in other groups.