Both clubs are stronger now especially now that there are more equipped with elite players on their teams and I think the current Manchester United is strong enough to take down Arsenal in a full time match. Haven't you been watching Manchester United pre season matches,they have been playing unbeaten and their performance was satisfactory unlike Arsenal who inspite of having the over hype Viktor Gyokeres was still defeated by Tottenham. In my own opinion & prediction in the match between Manchester United vs Arsenal, I think since the game will be played in Old Trafford, the home ground of Manchester United already gives the Red Devils a higher ground and greater chances of defeating Arsenal.