Duplicating Rigged Limbs

Hello all. After some help in another thread, I’ve managed to make a nice little IK rig for a War of the Worlds Tripod.

However, I’m having a problem with the legs. Firstly, the leg has about 30 bones in it for a smoother look during animation, along with one or two IK bones. What I have done is modelled a single leg, rigged it on its own separate armature, then weight painted/parented the bones as needed. Now I want to duplicate the leg to make two more.
What ends up happening is that half of the vertex groups get screwed up, meaning that the IK on the first leg affects the duplicates and certain objects, when the disconnected armatures are connected into a single rig, the duplicate leg objects immediately swing back into their original position yet are still affected by the duplicate leg armatures - the reason I assume is not only that the Vertex Groups remain from the old leg, but that the bone names have been duplicated as well.
A quick google search has told me that it is the Vertex Groups that are at fault, so to fix this, I either have to remove unwanted vertex groups and rename all of the other ones so that they conform to the correct bones, or simply remove all the vertex groups and re-parent all of the bones.
I’ve opted for the latter, as the model is quite simple and automatic weight-painting is a life-saver, but the whole process seems to be completely insane.

I’m circling around the issue, but this is the point: imagine if I had a complex, multi-bone limb rigged up and ready to be duplicated and I run into the same issue, but this time fixing the issue for each limb takes hours of time. How can this be avoided in the future? And if it can’t, then what the hell? How could this be planned around or prevented?

Thanks in advance for any answers, and sorry if the post is a little rambly. Whiskey and Blender are not a good mix.