I don't think Sastre is bad - but he lacks confidence.
The problem is that with Lucescu, we will never get a young team out there. You can expect that most of the new players we get, will be 32+ years old.
Greece has 5 berths next season. This won't change. Allocation is: Champions: CL q2; Runner-up: CL League path q2; cupwinner: EL q3; SL #3 and SL #4 CoL q2
If the cupwinner is one of the two teams that are qualified for the Champions League the EL spot goes to #3 of the league. #4 gets the #3 spot in CoL (does not change a thing for their start in CoL though) and #5 gets the final CoL spot.
So never more spots.
It is possible some teams start at a later moment in the European campaign due to rebalancing. As it is Olympiakos might start in the League Phase right away if the winners of the CL get an automatic ticket through their league.
Some kind of thing if the winner of EL or CoL also get a ticket via the league.
For more info see:
https://kassiesa.net/uefa/forum2/viewforum.php?f=12
This is a site for fans in the world and some excel-fetishists with up to date spreadsheet with qualified teams, seeding etc. It's fun to read.