Michael Bay said he would prefer to lower his fee in order to stay in the US to shoot his films. They are guys that have been with him for 15 years and knows how he shoots and can keep up with him.
I remember watching the behind-the-scenes stuff on the DVDs as well as listening to the commentaries and all I usually hear is:
Kenny Bates (2nd unit and stunt coordinator, associate producer)
John Frazier (special effects)
Who else are some other regular guys he works with?