I ran into that idea the other day and I thought it was pretty interesting, although I'd phrase it slightly differently:

"Rome's tradition of having to serve in 'lower offices' before the higher ones meant that when aristocrats inevitably ended up in charge of entire armies they had some level of practical experience and learnings to draw on while commanding".

But yes, much is made of Rome's redundancy in terms of military strength and there's a lot of states during that period that had A King who did everything and then died in a battle and then everything collapsed.