Why do people want Luis Enrique as new Barca manager? The only reason why he is linked with us is because of his past. Other than that, the only thing he has achieved in his managerial career so far has been failing at Roma. Same with Frank De Boer really, even though he is better than Enrique. But you shouldn't be losing 1-5 in a cup final or 1-6 on aggregate against Salzburg. If you want to play the Guardiola way and not change anything - or very little -, then any manager other than Guardiola himself will be a failure, or a copy that will never get as good as the original.
I'd actually like Martino to stay and have a transfer window to buy the players he needs. Team building is a very important skill for a good manager, and even tactically I think he is good enough. Provided the board and the players have faith in him and let him do what he feels to be right, of course. He has proved to be able to adapt when coaching Paraguay, who were very good defensively by the way. And when we started playing with quicker transitions and more counter-attacking elements (first half of the season) we were pretty good and on top of La Liga. But then players started to complain it seems...
But if he needs to go, I would want to see Roberto Martinez or Mauricio Pochettino. They play with very good counterpressing, but are able to adapt without changing much of their philosophies. Rudi Garcia could be good too. Roma rarely concede goals, and if I remember correctly they conceded just 1 goal in their first 10 matches, which is incredible. I really don't know how you can say he isn't a good manager and at the same time want Luis Enrique or even Arsene Wenger. If the latter comes (of course he won't), prepare to lose every match against top opposition by 0-6 or 1-5.