EC120 is their primary...
Wrong, you are thinking of the police force.
Army actually does do basic training on 135 as a result of highly successful lobbying from EC. They do a couple of hours of AR training on the 105.
My opinion: Ineffective as a primary trainer. Gigantic waste of tax payers money. There would have been so many better and more effective choices, but if they really had to obey to the EC people so badly they could at least have gone with the 120 option. This is a nice example of the difference between police and military aviation.