Draw calls and groups

Hello. I have a question about MED and models.
In MED you can arrange a model in groups or make a groups merge. That are good options if you are working on a model.

But does it have any effect if I would save a model that consists of groups without merging them?

If I load such model into the engine, would it end in more draw calls? Or is it always better to make a groups merge before you finally save a model in MED?

Yes, it would end in more draw calls, but it does probably not make much difference performance-wise as long as you don't have a mad number of groups.