The problem isn’t that they have cyno’s, the problem is that they have jump drives.
Giving capitals jump drives means they actually have BETTER strategic mobility than subcaps. Leading to capital umbrella’s. Capitals should be ships that have low strategic mobillity and be used in a deliberate manner against high value targets such as citadels and other infrastructure.
What if cyno was limited by number of ships that can jump through or by weight limit like WHs? Would surely put a huge inconvenience to current force projection.