It is not the same way.

It's not a separate entity but there's a much stronger degree of separation vs. the other Big 4 strategy teams. 

There are different rules and criteria for recruiting, compensation, training (yes, EY-P does 100% MBB style of training), staffing, progression. EY-P may work alongside EY colleagues in joint teams, but even in those cases EY and EY-P brands will both be kept in front of the client. EY-P even still has Parthenon's founder working for them and is a reference there (or had, until last year). On the other hand, it is a joint partnership, but one should stress that EY-P is gaining authonomy and not the opposite. I.e., more types of competences are being put under Parthenon and not on the side.

I would add that the fact that EY-P sits on a different service line than management consulting really helps with this. Management consultants sit at “Consulting” service line, that focuses more on technology; EY-P sits at “Strategy and Transactions” service line, focusing on Strategy, M&A and Corporate Finance topics.

As a general rule, it is very unlikely that you will not be staffed on a non-EY-P project if you are “Consulting” and vice-versa. Staffing within the Transactions service line may happen, but would be the exception rather than the rule.

As such, when you have peers not from EY-P they are usually from the transactions team and they have clear distinct (and complementary) capabilities, and as such the overlap with “competing” internal teams is significantly reduced. So the non-EYP people on the team can't really do my job and vice-versa, but we work as ONE team to deliver to the client. 

In other words, although there has been some cross polinization with the Big4 culture and processes, Parthenon still maintains the core of its “strategy consulting” DNA, and that is what makes it a success story and gives it a competitive edge. In short, EY-P is now a large strategy boutique/Tier 2, within a Big4 professional services team. This is clearly different from what happened at PwC and Delloitte (and Accenture).

Note: Just to reinforce the above, EY used to have a Strategy team within “Consulting” (usually doing transformation programs), and this team was separated from the EY-P team. In that case yes, you would have what you describe at PwC, but between the strategy team and the overall consulting team. However, this is no longer the situation, as EY realized that this Strategy team and EY-P were sometimes competing and moved the people with strategy consulting background to EY-P and removed Strategy from the Consulting service line offering/teams.

(edited)