The Sikorsky battle hawk demonstrator could have easily filled the role of the Cobra for the MC and then some, all while still leaving the utility options and parts commonality intact. As it is, even the Navy's MH-60S (as much as I hate a lot of its limitations) is very capable with its MTS, M-197, Hellfire (or guided or unguided rockets) plus a .50 in each door and M-240 in the windows. If we really wanted to make it a gunship on the cheap we could add some of the options from the -60G or L. and add miniguns or .50s to the gunners windows as well as 2 extra EWS stations.
Good thoughts, but I disagree with you on a couple things.
Here's the issue I don't think you're understanding, unless they mod the wing stubs on the 60s to prevent it from obscuring the door gunner's view, then you're essentially taking out the field of view for crew served weapons for that particular side if you mount hellfire on it. Secondly, we put a 20mm and 30mm on the Cobra and Apache respectively for a reason, .50cal and 7.62 are good for close in fight and suppressing the unobserved shot from the side, but if you really want to pound away at a target with good penetration from relatively far away with any accuracy, you're going to need a turreted 20 or 30mm. The TSS and TADs systems are way more integrated into wing stores and boresighted to the pilot's helmet and reticle for that reason. Fixed 20mm on a wing stub may have a lower CEP and mil dispersion, but you can only shoot that thing in a dive to be accurate, so it's just useless blocking a door gunner's field of view flying around unless your getting ready to tip in on something, hence the reason why an attack helo needs off axis cannons. Furthermore, let's say you do mount the turret of a Zulu or Apache on a 60, how is a the left seat of a 60 suppose to engage targets on the right side of the aircraft while trying to look through his copilot? or is he just going to be heads down in the MFD? Where's the turret going be put? under the chin? belly? Are the rocket pods and HMLs going to articulate and boresight to the sensor? If so, is that going to be a standalone HYD system? or is it going to have to be reworked internally? That's a lot of work and plumbing to do something that we already have aircraft for...so no I doubt a Navy 60s has anywhere near the capability of a Zulu or E model Apache, unless it gets mods thrown onto it heavily, and I feel for the poor avionics crew who would have to work on it. A SOF JTAC does not equal a conventional JTAC asking for a fire support answer, completely different customer and needs altogether.
You could slap stuff on and rig weapons systems onto an aircraft, but that doesn't mean it is the best airframe to do the job, much like the Harrier carrying AMRAAM discussed a little while ago. Does that mean the 60 can't launch hellfire, have CSW, and do OAS missions? Not at all, I'm sure there are plenty of situations in which that aircraft could be the low side answer. That being said, if you're going to go rolling deep into high threat indian territory, you're going to want to have an aircraft like an Apache or Cobra to run around and punch dudes in the face with flexibility and ease, and not a ghettoized half baked solution of an aircraft that was searching for a problem that never existed.