you target also scenes with big amount of entities, so this si for powerfull optimized engines for that purpose or some that uses like you said :
- bones animations on GPU
- Very Optimized shader system with deferred shading.

In fact you target some RTS using deferred shading ? i don't think it's the way to go ?
And massive entities like trees wihtout optimization you'll need some real instancing system :

Even on very old console : 2005 game Kameo ... WE ARE ON 2012 : 7 YEARS AFTER ... 3DGS should have a REAL INSTANCING ENTITY SYSTEM FOR ALL VERSIONS .... It's a VRY OLD FEATURE !!!







Just to push 3DGS further and improve

Well indeed :
- LOD on trees
- Distance shadow activation (character and trees)
- Distance Shaders activation
- Distanec animation for trees activation
- LOD Characters (distant oens with very less bones)
- Character sprites for far away entities ...
- sprites for trees also (far cry engine style)

There is so much amount of tricks, for optimisation ...

Yes 3DGS is not the best for complex scenes, shaders and lot of entities ... so you are making a complex game and would need some more appropriate 3D engine