I disagree with the notion that teams with vastly different timelines don't often win titles. You see it both ways, but going back to Boston's last title, there is a good mix where some teams like the Warriors are mainly aged together, but then you have the two most recent where there are pretty distinct age groupings even among the top players.
Lakers - Lebron is nearly a decade older than Davis and you basically had 2 groups i.e. LBJ, Rondo, Howard, McGee, Green and then Davis, KCP, Kuzma, Caruso with Morris sort of in between.
Raptors - Older Group - Lowry, Gasol, Ibaka, Green - Mid Group - Kawhi, Powell - Rookie Contract - Siakam, VanVleet
Warriors - top 4 or 5 generally in same range
Cavs - Older Group: Lebron, Smith, Jefferson, Frye, Williams - Mid Group: Love, Irving, Thompson, Shumpert, Delly, Mozgov
Spurs - Older Group: Duncan, Manu, Diaw - Mid Group - Parker, Green, Belinelli, Splitter - Rookie contract: Kawhi, Mills
Heat - Big 3 all from same draft, but they had old guys and young guys mixed in
Mavs - All older though had a few guys like Kidd on their last legs
Lakers - they had Bynum and Fisher who were clearly not in the same range as Kobe, Pau, and Odom
Celtics - Big 3 same general timeline, but lots of young guys mixed throughout the roster