Take a long term view and go step-wise.
First step is convincing Pandits to go settle back, which can be incentivised but its going to be tough, particularly if there aren't separated clusters.
Next step, of those who do go, some will obviously suffer due the inevitably extreme Muslim elements. That is what you use to make an example out of and utterly and completely crush. If you fail there, the Pandits would again be on their own in effect. Obviously, you can't keep protecting people in perpetuity.
Even if you have separate clusters, what happens to people when they step out or are they to be confined in those enclosures forever?
Lets be blunt, this is never going to be a completely peaceful process. Its the political will to ram through and crush the violence that matters.
Don't get me wrong, I have nothing against armed kibbutzes but eventually you'd have to phase them out. The point to note is that opposition to this is used as an excuse by those don't want the Pandits to return at all.
If we can't get this done now, with BJP at center and part of government in J&K, its unlikely to happen in the foreseeable future. My central argument is that we cannot allow any more delay.
Bottom line, if the center can push through separate colonies, great. If not, go with what you have and work with it.