I was very impressed with Grand Komodo when I dove Komodo a couple of years ago. Their guides really know the area and can read current very well and gave excellent dive brief. I remembered one particular instant where the diveguide warned us, to dive from A to B, don't go beyond the 2nd rock outcrop because current would be bad etc. Since the dive was very easy, of course as we reached the 2nd rock outcrop, I just had to see what the fuss was about not to go beyond that point, let just said that I found out the hard way

It is a must to have a guide who is very familiar with the area and current for Komodo.
I think it is important to have local personals on board but I don't know what is consider a good number, 10%, 50% of the crews? It is definitely more essential to have local guides but local boat crews does not add much benefits to the boat except for moral reason, I suppose, you make money of the place so give something back to the area as well. Unfortunately this does not happen in many many instant, not jsut the Thai boat in Indonesia but yes, the good form would be to help the local out as well.