I am making a 2d game where there are various environments with lots and lots of objects. There is a forest scene with like 1200 objects in total(trees mainly), of which around 100 are visible on the camera at any given time, as you move through the level. These are comprised of around 20 different kind of trees and other props. Each object is usually 2-6 triangles with a transparent texture.

My developer asked me to replace each object in the scene with a node, and keeping only a minimal amount of actual objects which would be 300+ or so(?), since there are a few modified unique meshes. So he can instantiate the actual objects to keep the game light.

Is this actually effective? And if so how much?

I 've read about draw calls and such and I suppose that if I combine each texture (10 kinds of trees) in 1 mesh it will have the same effect?