I would say he is - one of a select few to have won 3 CL titles, more than Pep and Mourinho and massively less hyped than those 2.
He's defo great.
But it does help playing teams like Eibar every other week.
Eibar are a one off.
He's done it in a weaker league: the Premier League.
He has been a manager for longer though. Admittedly I don't rate Guardiola as highly as most -- he did a great job with Barca but if your only two jobs are with Barca and Bayern in their peak, then surely it's not as bulletproof a record as someone like Mourinho, who has done it all over Europe and even with some weaker teams.
Ancelloti is a classy guy though. Having a dream team is one thing but actually getting it to play like one is harder than it looks.
Good point that the Guardiola knockers would do well to take into account. Re Ancelotti, true he's been a manager longer and has probably also won less league titles I would've thought. CBA checking but he think he only won 1 or 2 with Milan in 7 years, 1 at Chelsea, an easy 1 in Paris and none in Spain so far.