P-61s were capable of and used more than one way. They are essentially slightly slow Mosquitoes with more climb and maneuverability. With 4x20mm cannons, they can and did provide ground support. The A-20 has been in the game for a long time without a problem, there is no reason the P-61 can't be added and function just as well.
This is the same game where B-17s have been used as dive bombers and low-level ground attack. Where high-altitude fighters spend most of their time below 10,000 feet. This is a game where the Fi 156 was added to the plane set.
I won't list all of the twin-engined aircraft in the game (there are quite a few). But most of them overlap in performance and capabilities. Where is the Beaufighter? Where is the A-26? The Beaufighter may be outclassed by the Mosquito, but so is the A-20, Ju-88, and Bf110. The A-26 is "too good" and would unbalance the plane set... like the B-29? The P-61 has better performance than the early twins and only slightly inferior performance to the Mosquito (though with better climb and turn capability). Without the radar and the night fighter role, it would still be fun in the attack and fighter roles of the MA and no more of a hangar queen than so many others that are already in the plane set.
