Yeah I guess you're right. On second thought, I'd probably agree that his hair loss isn't severe enough to warrant Dutasteride. If he finds later down the line that finasteride isn't stopping his hair loss, he could then consider dutasteride.A bit too drastic. I had more severe hairloss younger than him and just finasteride 1mg have been enough to stop the hairloss and give a bit of regrowth.
Sure, dutasteride will be more effective in terms of regrowth but I think finasteride + minoxidil would be the right choice starting off.