Conte used to spank Garcia, Enrique, Benitez etc... in Serie A. Just the way he is doing it now to Mou and Pep. He is obviously a master at league competitions (would kill to see him go against Ferguson).
As for your points,
(1 & 2) they have infinite money true, but so does everyone else in the top 4. Dont forget they are in their 1st seasons unlike Spaletti and Sarri
(3) They are not facing weaker competition with stronger squads for CL seats. Arsenal, Spurs, Liverpool, Chelsea have very good squads. The gap between UTD/City's squads and these teams is certainly smaller than between Roma/Napoli and Fiorentina, Lazio, Atlanta, Milan etc... Inter is the exception (they should be easily on par with Roma and Napoli on paper imo).
(4) the direct rival is Juve (heads and shoulders superior to them with or without the signings and not exactly a rival for 2nd or 3rd). I am arguing that its tougher to finish in the top 4 (2nd,3rd,or 4th) in EPL with UTD/City squad competing against Pool, Spurs, Arsenal and Chelsea, than to finish 2nd or 3rd in Serie A with Roma or Napoli's squad. To me thats obvious IMO. Top 4 in Germany for example with BVB's squad is easier than Top 4 with City/UTD and Top 3 with Roma/Napoli.
I know we will probably continue to disagree nevertheless
Seriously though, if Allegri leaves at the end of this season (for the sake of argument), and you can hire for Juve either Mou, Pep, Sarri or Spaletti, you would go for Spaletti over Pep or Mou?
I like Sarri and I think he can go places with a stronger squad but Spaletti is hopeless imo. We would be humiliated in the CL on a yearly basis. I'd take Wenger before him and I think Wenger is shit.
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On a week by week basis yes they look more stable than the manchester clubs but head to head I think the small team mentality would kick in. Roma especially has horrible stage freight. City looks good in the CL this year