Arsenal reportedly ignored the advice of their head of recruitment Francis Cagigao before signing Lucas Perez and Shkodran Mustafi.
Perez and Mustafi both moved to the Emirates Stadium in the summer of 2016 for a combined fee of around £55m, with Perez costing £18m and Mustafi close to £37m.
Both players have since struggled to live up to those price tags, though, with Perez making just 21 appearances for the club before leaving two years after his arrival.
Mustafi is still at the club, meanwhile, but has regularly been criticised for his error-prone performances during his 133 Arsenal outings.
The Athletic reports that neither player was on Cagigao's list of recommended signings when Arsenal were in the market for a new centre-back and striker, but that the Gunners instead went with statistical data provided by Stat DNA.
Perez is currently playing for Alaves in Spain, while Mustafi has enjoyed something of a revival at Arsenal since Mikel Arteta took charge of the club.