I am aware that one can be an AROTC cadet while also serving as a member of the army reserves or army national guard, but can one be an AROTC cadet while also serving as a member of another branch's reserves or guard component?
You could, until it's time to contract, then you would probably have to leave the other component. Didn't confirm that in a regulation, just an educated best guess, and I'm with jcleppe...can't think of a good reason why you'd want to do this.
When my son was an MSIV, there was an AFROTC cadet in his USAR unit. I believe she was engaged or married to an older AFROTC cadet which was her reason for pursuing the transfer in branches...That was a year (Spring '14 or '15?) where the AF decided to limit the numbers going to Summer Camp/Advance status. I know she then talked to the AROTC cadre, but heard later from my son that she did not contract.