Isometric 2D images mixed with 3D objects ?

Hey

So I'm looking into making an isometric game using mostly images for the illusion of isometric angles. How ever, I will want to use 3D objects for certain things that need to rotate in 360 degrees - mostly characters walking on screen.

So i'm really new to unity and so far have my camera set up to orthographic isometric angle. But I am curious as to whether or not it matters regarding how I use my isometric sprites.

Currently I just drag them into the hierarchy, but then i wondered should i maybe add these images to a plane as a texture ?

My worry is i pick one of these decisions then hit a problem later on that I did not foresee. So i thought I would check if simply using 2D sprites rather than planes with textures is a good idea, is this how most isometric unity games are done ?

As extra - i don't suppose any one recommend a good isometric unity tutorial - i can only find basic ones for setting up camera, but not building a simple isometric map with game mechanics.