Multiplayer was/is easymode.
If you cant kill moder with 2 men you definatkly will never kill it alone

Old values
Alone
Player 100% damage
Player 100% HP
Moder 100% damage
Moder 100% HP

2 men
Player 200% damage
Player 200% HP
Moder 104% damage
Moder 140% HP
Means you have 400% Bonus (damage over HP)
Moder has arround 150%