Personally I think the orbital strikes should take on the form of a prolonged EMP effect for all 3 factions. Why?
- There's a chance to fairly counter it in that you aren't just "dead".
- Relies on tactical usage not just "grid x looks likely target - just carpet bomb it even though theres no friendlies there to make use of it" in order to get the damage payout from it you've got to have troops on the ground to dish that side out.
- Still can be used as a siege breaker for prepping a force to be hit hard.
- EMP drops the shields among other effects for any side caught in it so you've got to make sure you're placing it correctly theres that "punishment" if you get it wrong.
- EMP could be used to affect gate shields/electronics etc of any base defense which gives it more versatility.
- Probably look graphically more exciting than just explosions everywhere.
Most mentioned already but I don't think the OS mechanic has to be strictly damage front orientated for them to be fair, useful and deadly.
The carpet bomb effect could be co-ordinated through a galaxy/liberator cluster bomb drop or something that relies on more co-ordinated use than a fire and forget.
Getting hammered by a bomb OS then hammered again by A2G, then swept up by a tank and infantry push would be demoralisingly repetitive I think and not invoke as good team work. Yes there will be those that might argue this is how it "works in the real world" but isn't necessarily a good game mechanic.