I wouldn't be surprised if they didn't understand that testosterone can't be 'supplemented' in the normal sense because of how it operates. If somebody gets a testosterone supplement, your own body will stop producing testosterone. And if you ever stop taking the supplement, your own natural production may never return. So it's often a one-way trip. If you're on t-replacement, you're on t-replacement for life.

An army that would fall to pieces without a constant supply of testosterone supplements is probably not going to be the most effective fighting force.

There are ways of more cleverly nudging testosterone (and estrogen) production without directly supplementing. https://pmc.ncbi.nlm.nih.gov/articles/PMC5009465/