The duo Premier League giants have moved relatively quickly to seal top signing at this early stage of the transfer window.
But top-class goal scorers are in particularly high demand across Europe right now, meaning neither Jose Mourinho nor Arsene Wenger could afford to lose out on their key targets.
It will be interesting to see which of United’s and Arsenal signing proves to be the better signing over time, especially considering both might have ended up at a variety of destinations this summer.
The former Chelsea man was on the verge of joining his former club Chelsea before United came in, while his now Arsenal rival could well have moved to Old Trafford instead of him.
The Red Devils reportedly sent scouts to monitor the Frenchman during his final season at Lyon after Mourinho took not to his brilliant goal scoring abilities.
Lacazette finished up with a total of 129 goals for the Lihue 1 champions, including 85 in appearances since 2014.
It goes without saying, that the 26-year-old could do little more to confirm his status as one of the deadliest strikers on the planet.
However, Mourinho decided not to pursue him after having a scouting operation assess his quality down to the finest details.
The reason being, according to the Guardian, that the Portuguese manager was told of reservations about his physical attributes, big-game mentality and overall suitability for the Premier League.
Arsenal scouts, on the other hand, clearly saw no such problems while observing the man who would become their new £52.7 million striker.
With Lacazette off his radar, Mourinho turned to Lukaku – a player who outright trumps the France international in terms of physical presence and pedigree in the English top-flight.
The former Chelsea star was always going to command an enormous fee having racked up 85 league goals with Everton and West Brom since 2012.
But while Lukaku already knows his way around the Premier League, it wouldn’t be wise to assume Lacazette has no chance of proving those United scouts wrong.