They finished close to relegation last season, and I don't think they have that many good players. Biggest factor was Miccoli keeping them alive by being involved in ~60% of their goals, this season he has slowed down. It didn't really matter whether they had 5 or 6 different coaches, he kept scoring and creating.
for all we know,viola might get a tough draw in the cl playoff so its not certain that viola and jovetic in particular will be playin cl football next season if he stays on with them.