I'd like to be able to take my newborn, give them a large round shield and a big axe, and put them in the shieldwall, Sturgian-style.
No, really. I'm not saying it would be realistic, or expect it to happen, but I'm still miffed I missed the chance to play as a Wartot before the battle-kid R-glitch in character creation was patched out, so that's the next best thing. Also, I have a questionable sense of humor.
With that out of the way, some means of "training" offspring would certainly be helpful. Whether by paying for "tutor" characters, or sending them off to be raised by other lords (kind of like the player already does in "Lord/Lady needs a tutor," only not just restricted to "age of majority" years).
Would be nice, and in gameplay mechanic terms would prevent you from having to grind yet again from the bottom if your original character kicks the bucket. So you can focus on the more important, then, things, like ruling a kingdom, or at least a sizeable clan.