How old are you? Drugs and alcohol are bad for you.
First of all, united is in no way 'much bigger' than AC. United is not that much richer (if at all),
United probably don't have that much more fans wordlwide and the brand Manchester United is not worth that much more than the brand AC Milan. Im not a historian but i dont think United has won as much as Milan as European wise, and more famous players have played for AC Milan.
Second, comparing Arsenal with any Italian team is comlete
Their history, silverware, playing style.... none of it is even remotely similar