Have more stations will not solve the problem of over crowding.
Only having higher frequency of trains or larger / longer trains will help.
higher frequencies of trains and longer trains will not help, as i've said many times. size of tracks and tunnel width dictate size of cars, and therefore larger trains are out of the question.
higher arrival frequencies: will not solve problems at congested transfer stations and segments of routes as passenger arrivals (from other routes) exceed the possible highest number of train arrivals. for safety reasons and smooth running of trains (as track lengths and number of stations are limited per route due to size of island), it's better to keep the arrival frequency at an optimum, with a margin of error of 1 minute or 60 seconds. tighten the arrival frequency further, and the system may be asking for accidents. it's that complex and complicated due to the entire picture of multiple trains running simultaneously with multiple stops, multiple holding times, deceleration and acceleration factors. that's why a powerful computer is needed to run it and re-configure everytime new routes and new stations are added.
longer trains: will not solve problems of congestion as each station is limited in length. new car lengths will also not overcome the station length limitation issue. most rapid transits in the world's systems are limited to 10 cars max.
solution: alternative routes, alternative transfer stations, parallel routes, parallel transfer stations, multiple choices in route interconnection so riders can avoid congested areas with shortest possible rerouting times. this problem is solved by internet protocol routing, and the new system closely approximates that.