To my understanding,BOTH players aren't content with the current setup(Bravo->Liga/Mats->CL and CDR).
BOTH of them made their disappointment and desire public.Whether you want to call this blackmail or just informing the people and the board is up to you.So, both players more or less threatened to leave if they wouldn't become the #1 goalkeeper in both the Liga AND the CL.(I am not saying it is wrong.Both are professionals and have to care for themselves).At this point,the board could do the following:
A)Choose either of them and inform the other one that he either has to settle with CDR and occasional matches in La Liga and CL when the #1 is injured or leave.This is the most honest thing to do.
B)Make both of them settle with the current setup(or a variation of it,possibly the exact opposite),which frankly is really hard to do,as not one,but both of them want more.
C)Deceive the one of them into thinking that he would be #1 and have him on the bench.This would make a huge fuss and would most probably result into the player leaving ASAP.
The club chose option (A).MAtS and Bravo are at a similar level.Even assuming that Bravo is better than MAtS,the difference isn't that big.However,MAtS is almost 10 years younger,which means that it is far more likely that he is the one who has more to offer in the long run.
This IMO was the right choice.Ofc you can never accurately predict what the future holds.MAtS can either live to the hype and become one of the best GKs in the world or suddenly lose even his current ability and become a mediocre keeper.Bravo can play at this level until his 40s or have an injury or two and retire.BUT,the most likely thing is that MAtS will at least keep this level of performance for many years,while Bravo will sooner or later deteriorate.