One thing to keep in mind.
If you are unable to transfer your 3 yr scholarship to OSU then I assume you would be doing ROTC as a walk on non scholarship cadet. Remember that you would be unable to contract until your junior year unless you are able to get a campus based ROTC scholarship after your first year,
The ROTC battalion at OSU will be larger then the unit at SC. There is a good chance there will be more MS1's then there are contracts available come your junior year. You would be in a much more competitive environment at OSU, you run the risk of not getting a contract which would mean you could not continue in ROTC past your sophomore year.
You have a much better chance of getting your contract at SC with the 3 year scholarship, you would contract the first day of your sophomore year providing you pass the APFT and meet all the requirements of the contract. Once you are contracted you must just abide by the contract and you will commission when you graduate.
Just a couple things to think about, the Army is getting much tighter on contracts, the less risk the better if your goal is to commission.