Once enlisted there are no age restrictions on commissions, at least in the army.
When I was enlisted, lo these many years ago, a sailor had to complete the requirements by age 30 to be considered for an unrestricted line commission. After that the choices were Warrant Officer of stay in the enlisted ranks going for E-9.
Masonic consideration - We are taught to drop superfluities out of our lives. Do the necessary but not the unnecessary. There is no necessity to be enlisted before taking a commission. It behooves us to recommend the most efficient path to success. Within the military success is largely but not exclusively recognized with rank, therefore starting at the highest rank available is the most efficient path. Starting enlisted is unnecessary and about something not on the direct path to success.
And as far as reaching Flag ranks its something like less then 1% that reach that anyways.
So we should make recommendations that push that percentage as low as possible? I think not. Set those goals high!
And he wants to go supply/ logistics that makes the chance of getting that high even lower.
On the other hand the competition for rank is lower within the supply corps. Promote where the competition is lowest as a restricted duty officer, then transfer to unrestricted line officer to be able to continue advancing the highest. This is an optimization problem - Analyze the numbers. Advance within the supply corps while the numbers say the advancement is faster then start applying for unrestricted line officer status when the numbers say the advancement is farther.