It cant be fixed through a mod as it requires recoding of the DeployStyleAIUpdate code.
You can help to improve the problem by doing what I did;-
1 - putting the 'Guard Without Pursuit' instead of the normal 'Guard' command on its CommandSet. Its not like Nuke Cannons will ever catch up with much, and this helps to reduce the problem. In normal guard mode, it will redeploy every time as it tries to 'pursue' its target(s).
2 - Give it the 'fire weapon at location' command on its CommandSet, as when ordered to bombard a location it stays deployed and continues firing until given another order.
None of those things truly fixes the problem but between them they do help to improve the Nuke Cannon so it becomes something very close to what it should be for the Chinese player.