I felt they gambled on getting Mourinho. Gambled that they had an elite squad, a sort of champipns league finalist- top 2-3 in the league sort of squad and that Pochettino's lack of experience of winning trophies was holding them back. Rather than havijng to sign loads of players, they could just get a winner to coach the existing ones/organise them better.
I do think that has backfired, even before this season. The form under Mourinho last season was not top 2-3 form. He imrpoved them, but not substantially, and he got lucky with the break, as the wheels has just come off.
They look an ageing squad to me. They kept the squad together for too long and didnt freshen it up. You will generally always decline if you do that. You trade a couple of years stability for collapse. A lot of their players arne't eve so older, late 20's, but if you don't buy new players in, and just keep putting your existing ones on bigger and bigger contracts it catches up with you.
The question with them, is really how messy does it get. I don't think there will be any loyalty to Mourinho as there was for Poch.