Well. it very well could end up an ego-driven disaster, but I wouldn't be that sure about it. The thing is, this is not uncommon in the environment Paratici knows best, i.e, Italy. He himself played the 'Lange role', for lack of a better term, at Sampdoria and Juventus - working on the scouting and player identification while acting as a protege to Beppe Marotta, who made the main decisions on whom to bring in and for how much.
Not like it was particularly short-lived, either. Paratici was Marotta's protege and second-in-command for something like 14 years, from the mid-2000s through to 2018 when he took over the role.
But, the key is that there has to be an awareness of roles and responsibilities - Paratici found the players and set deals up, but Marotta decided which ones were worth pursuing, and closed on them accordingly. There's a clear hierarchy there, which is why it worked.
It fell apart when Paratici started trying to bypass Marotta by currying favor with Juventus's owners, the Agnellis - the Ronaldo deal was the trigger for Marotta leaving, as he felt Paratici had undermined him by working with Andrea Agnelli to get that deal done, while he himself had been against it.
Marotta subsequently went to Inter and revitalized them, Paratici fumbled at Juventus and then joined us as the plusvalenzia scandal made Italy too hot for him.
So - all that to say, it could work, but it needs a clear awareness of who is responsible for what - and a deference to hierarchy.