I agree with AROTC-dad.
Joining SMP means you would be enlisting in the National Guard, if you do this you will lose the Scholarship you just earned. As an enlisted National Guardsman you could apply for the GRFD Scholarship which pays the same as the Scholarship that you now have, the BIG difference is that with the GRFD Scholarship you will not be allowed to commission into Active Duty, you would be required to serve in either the National Guard or the Reserves.
Next you will not be a SMP cadet until you contract with ROTC, that can take up to two years, during that time you would be deployable if you have completed both BCT and AIT. That brings up another issue, when would you go to BCT and AIT, would you miss the first half of college? You can do SMP without going to BCT or AIT but then you would not receive as much tuition assistance unless you took the GRFD, which again means you aren't going Active Duty.
You can do SMP without the GRFD and you can compete for Active Duty, but you will be required to attend drill one weekend a month every month even during school, are you willing to give up that one weekend every month?
SMP will not give you a competitive edge, you will compete with every other cadet under the same OML.
Recruiters tell a great story, frankly the fact that you already have the scholarship I'm not sure why you would even be talking to a recruiter, their job is to get you to enlist, period. You're going to school and ROTC to be an officer, no need to add something extra to an already crowded plate.
You already have a 3 year scholarship in hand, there is always a chance to be upgraded if you show up ready and work very hard.
Bottom line, stop talking to the recruiter, talk only with the ROO and Cadre from the ROTC program you will be attending.