Ooh, ooh, let me latch onto this.
Lets look at the M4 being introduced alongside the AK for commando. The AK is a solid-hitting hipshooter of a gun with a slightly lower rate of fire and a good amount of recoil. Next to it is the M4 with very low recoil, high accuracy, and a very high rate of fire, but less power, but more magazines. The M4 functions like a bullpup for a different tier.
The MP5 with flashlight should fit into an AK-like role on Tier 1, with a 30 (or 34 like the medic) round capacity, complete with the commando's bonuses on top. A little more recoil than the bullpup, a little more power, and overall same ammo, though less ammo per mag gives a greater total of complete magazines compared to the bullpup, which is good for those who prefer smaller magazines for ammo control purposes. It also holds it value in the later waves thanks to its flashlight. It should also have a similar price to the bullpup, if not the same.
No exact numbers, but that's my opinion of how the MP5 with light should be.