I am think that the idea of having Navy and Airforce provide rear security and services is good
The high technical nature of the many trades they could assiting with salvage of high components or repair of vehicles, gun systems ect, this could free up other army personel to provide combat troops replacment.
IRL the USN Navy Provisional Detainee Battalion 2 was formed for duty in Iraq under the coomand of the US Army's 16th Military Police Brigade
http://en.wikipedia.org/wiki/Navy_Pr...ee_Battalion_2
Also the Canadian Navy has provide Clearance Divers to Army for Counter IED duty in Afghanstian, most notable was Petty Officer 2nd Class Craig Blake who killed in Afghanstian while attemting to disfuse an IED -
one of the best divers I ever met