I really wanna find out how much heavy lifting is the radar doing on these arh missiles
The missile own radar is what matters and they are all copy paste in that aspect.
The platform radar is only important for actual searching for something to shoot at, and keeping a lock/softlock for initial heading guidance.
Maybe the radars that have a quick narrow TWS scan pattern help a bit with faster datalink but you can always hardlock with any of them anyway.
Make a mod with the su27sm and give it su34 radar (it is used as placeholder for N011M in dev rn), thenalso make other mod with su-27 with r77-1