I think, succession plan comes from leadership in Cricket. In other team games like soccer or Basketball, it's the Manager/Head Coach who is the boss and he plans his squad, strategy, succession plan. Cricket is a bit different, because here the man run the show is Captain.
Also, in Soccer, these days financials play a big role in succession plan - most Managers have a budget and they don't want to run in a situation where more & more players are touching 30, approaching last years of contract and consuming high wage with low to nil salvage value (transfer fee). In soccer, average squad age of a club owned by a sugar dad is often higher than a squad of managers like Klopp or Wenger or Pochhetino. Similarly, despite most players retiring from National duty by early 30s, International teams have a higher average age in WC/EURO (& Qualifiers) than top clubs in same league year, because National Managers don't bother for succession plan for a tournament - they use friendlies for that and pick most experienced and inform 23 to tournaments.
Over the last 15-20 years, PAK had been led mostly by compromised choices - either Captains who don't merit in XI or Captains who are not natural communicators/leaders and almost every Captain was insecure. In such cases, Captains tend to protect their arm-band by surrounding trusted people, and safe people (less ambitious). Also, most of the Captains appointed were not good man managers, rather they opted players, whom they can manage easily - aka group mate.
Besides, PCB didn't help Captains by appointing them series by series, instead of long term (like next WC or next AUS tour ...) - this makes Captains insecure and safe player; often they would opt for known faces, players on reputation and most importantly, they tried to keep influential players comfortable, never challenged status co.
All these results into a generation gap, always - a bunch of players keep scratching each others back and they remain united, which will always result into increase of average age for the squad (because the core bunch is kept regardless of performance for years).
Operating with younger players needs lots of patience, guidance & mentoring; which none of two long term Captains (IuH & MuH) were comfortable, rather they were happy to have an experienced squad, where it's easier to delegate. And, one needs BIG heart to drop own cousin & mentor for a kid, because that cousin didn't merit place any more.
