THIS IS NOT A PHYSICAL BATTLE.
the American Government is sick of Batman being a vigilante and taking the law into his own hands.
The Government hires L, Near, Light(AS L #2), AND Mello to deduce Batman's identity.
2 Different Situations:
1st: All 4 of them are working by themselves in their own HQ. NOTE; In this situation Mello has Matt.
2nd: They are all working together. NOTE: Matt is NOT in this situation.