The Gunners wrapped up a club-record £52m deal to bring France international Lacazette to the Emirates Stadium from Ligue 1 side Lyon.
The 26-year-old arrives at the north London club fresh from scoring 28 times in 31 games in the French top flight last term.
Manchester United hijacked Chelsea’s attempt to sign Lukaku from Premier League rivals Everton earlier this week.
The Red Devils agreed a £75m fee with the Toffees to make the centre-forward their second-most expensive signing of all-time.
The Belgium international scored 25 times in 36 games in the Premier League last season, finishing behind Tottenham Hotspur’s Harry Kane in the goal-scoring charts.
Asked during ESPN FC’s Extra-Time show which striker would score more league goals next season, former Newcastle and West Ham goalkeeper Hislop said:
“Lukaku will score more goals [than Lacazette].”
Lukaku moved to Everton from Chelsea in a £27m deal in 2014 after Jose Mourinho deemed the striker surplus to requirements at Stamford Bridge.
However, in a twist of fate, Mourinho has now made Lukaku his main striker at Old Trafford.
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