I'd push that just a bit further. Make webelos start a year earlier and last a year longer, so 4 years instead of 2. A lot more new scouts are afraid of the outdoors because fewer parents camp, so they're even less mature than before. So make the program about getting them ready to camp with a troop. And as you said, make it part of a troop. If a webelo is mature enough to move to a patrol when they're 11 then go for it, but most aren't. Anyway, as part of a troop they'd still have their own program but they'd see the scouts, get to know them and the transition would be easier.
If this were done than cubs could be skipped all together. Yeah, I know, that will go over like a titanium balloon (lead's not so healthy ). So, end of my 1 1/2 cents of wisdom.