Basically in UNIVERSE MODE or whatever you gonna call it, game will generate tours for different teams , a particular tour can include 2 FC games , 5 ODis , 2 T20s and 3 Tests, it can be tri nations ODis series , Tests only tour and whats not , you can choose to play/sim the tour edit it or can discard it completely so that a new tour can be generate , players skills will increase or decrease based on their performance then there can be team rankings for Tests and ODis ,players rankings as well , sort of like a mini career mode without players aging and retirements , shouldnt be hard to code as well.
But I would prefer normal management style career mode over it , it just can be add to add replayability to normal exhibitions and matches.