Would really like to see these get added, right now we're limited to scorpions for the ar'kif or scorpions and drones for the scimitar, outside of a limited selection of federation hangar craft that, frankly, no self respecting romulan would use.
The tiercel shuttle would launch 3 at a time, 6 per hangar, with one plasma beam array and one plasma torpedo launcher. Special attack could be fire at will.
Kestrel runabouts would launch 2 at a time, 4 per hangar, with similar stats to the Danube. Plasma dual beam bank, plasma torpedo launcher, beam overload, and the quantum absorption singularity ability to lend some extra survivability. More advanced versions might have emergency power to shields or aux to structural for self healing.
Would also like to suggest an entirely new hangar pet for romulans: singularity drones. These sphere shaped drones will not stray from your ship (but can still be docked or released with carrier commands). They are equipped with a plasma beam array with a 360 degree firing arc, but will only fire at projectiles, mines, or enemy fighters.
The singularity drones launch 1 at a time, max of 2 per hangar, and serve as a hybrid point defense system and singularity capacitor. For each drone you have active, your singularity charge rate is increased by 10%, and singularity cooldown time is reduced by 10%. This allows you to use singularity abilities more often and regain singularity power more quickly at the cost of losing offensive hangar craft.
Advanced and elite versions of singularity drones would only gain increased hitpoints and shield strength to make them more resilient, much like shield repair shuttles.