[_s]

I'd argue you need this split - managing people is different skill set to managing a project, which is different to managing the technology, which is different to managing a product.

They do overlap, but to me there is a clear line between their responsibilities and authority. Things get blurry in smaller orgs, but in larger ones with multiple product streams, budgets and stakeholders - they're usually pretty clearly defined roles.

[liquidpele]

Like many things, it sounds good in theory which is why many try it... but in reality it often turns to shit because you end up with 4 quazi-managers all stepping over everyone else and constantly asking the team to do extra work (like generating data/reports or attend meetings) that's really their own damn jobs because surprise-surprise being technically capable of more than making spreadsheets wasn't part of the original job requirements.