Horner has to "work on the maths" regarding lost Mercedes F1 staff - Wolff
Over the Miami Grand Prix weekend Horner shot back at suggestions from Mercedes and McLaren that Red Bull would be weakened by designer Adrian Newey's departure, and in particular McLaren CEO Zak Brown's belief that Newey "won't be the last domino" to fall at the team.
Horner claimed his newly built-up engine division Red Bull Powertrains had captured as many as 220 people from Mercedes High Performance Powertrains in Brixworth, and suggested that his squad had also attracted a significant number of people from Brown's team.
"I don't know how many people we or RB have employed from McLaren this year," said Horner. "We have taken 220 people out of [Mercedes] HPP into Red Bull Powertrains.
"So, when we are talking about losing people, I would be a bit more worried about the 220 than maybe one or two CVs."
But Mercedes has strongly contested those numbers, with Wolff claiming the actual figure is just a tenth of that.
"You have got to work on the maths - 19 engineers," Wolff said in Imola.
"Whatever those numbers are, there are natural fluctuations that come and go, which is completely normal."
George Russell, Mercedes F1 W15
George Russell, Mercedes F1 W15
Photo by: Mark Sutton / Motorsport Images
Ahead of 2026's regulation changes that will put a bigger emphasis on the hybrid component of the power unit, the job market for engine experts has been extremely competitive as the number of manufacturers climbs from four to six.
In addition to Red Bull deciding to build its own engines, which has required a massive investment in the RBPT division at its Milton Keynes campus, new entrant Audi has also gone on a recruiting spree as the German manufacturer gears up to build its first bespoke F1 engines.
But Wolff says he is adamant his Brixworth team is in the best possible position to continue being a benchmark, having stolen a march on the field in 2014 with the first iteration of the hybrid power units before others caught up.
"We have an engine department which is as good as it can be with a top leadership," Wolff insisted.
"There is not a millimetre that I wish would be different in terms of organisational set-up, in terms of the people that work there that I am lucky to interact with. It is just a perfect organisation and you can see they are delivering, and they have delivered for a long time.
"Since 2014, we have been pretty much the benchmark, or with another engine maybe, the benchmark. That hasn't changed.
"I really can't wait for 2026 to come and see the different levels of performance of the power units."