It does confirm how difficult it is to create a young character with the life path system. Using only this, it becomes an "old man's war".
If were to run a game with my group, I would consider reducing the age increase to 1d3 or 1d4. At least for the first three segments.
That is true. But historically, wars, especially total wars, have cut down the youngest generation the most. T2K obviously cannot simulate that and shouldn't try to for the sake of abstraction, but if you're too young, then the war starts, you're reaped in the first high intensity campaigns. Then, if you're conscripted in the late war, you're thrown into Operation Reset without good training. So those that survive are the one's that got lucky or already had enough skills accumulated, once they entered combat.
Regarding the age increase, I must say the d6 seems to random for me. Especially considering certain ranks and promotions in the military, you cannot start as a second lieutenant, spend one year and get promoted to first lieutenant. At least not in militaries I know, and this get's worse with higher ranks. Yes, battlefield or brevet promotions might be a thing in World War Three, but not before the war and even during a war that get's ludicrous at some point. The same goes for civilian careers as well, of course. You just don't go from college to finalized PhD thesis in three years, this isn't the 19th century any more.
Summing this up, I'd think that a range of up to six years can be a good thing, but I'm not a friend of the big range and the minimum set to just 1 year. Since T2K doesn't use D4s, but uses D3s, I could go with D3+2 or D3+2 for careers. The latter would obviously give you slightly younger characters on average. Having an average of 3.5 years between promotions still can be awkward, but it's better than just 1 year.