NMM Controller voiced concern regarding military operations that result in several aircraft operating in close proximity to one another making accurate traffic calls difficult.

Narrative

Aircraft X departed Key Field VFR with a request for IFR approaches. When able I cleared the aircraft and gave it a southbound vector towards the ILS Runway 01 final; at which time the aircraft reported traffic in his vicinity at 3;000 MSL and requested to not accept my vector. I instructed the aircraft to turn at his discretion; and it was about this time that I was able to identify the target he was referring to. The problem of my not being able to see the aircraft and issue traffic; or not give the vector towards it; was because five other aircraft from the same command as Aircraft X (Aircraft Y; Z; W; U and another) were airborne within 6 DME of Key Field and the alpha-numeric clutter prevented me from seeing the unidentified VFR target at 3;000. This has been a constant problem with this squadron. At one point; several months ago; the Commander agreed to not allow more than two or three of his aircraft operate over one operational area at a time (they routinely operate over Key Field and a fix referred to as Sand Flat; which is located approximately 3 NM east of the airport); now they routinely operate 5 and 6 at a time. Key Field is the main civilian airport in our airspace and it hosts practice approaches on a regular basis (Navy; Air Force and civilian). The training these aircraft are engaged in require ground personnel stationed at relatively fixed locations. They need to use a location that is not in close proximity to; or over; either of the main airfields in our airspace.