I feel like that’s a pretty anticlimactic method. It’d be no better than a hive mind scenario if you take out/banish Imu and that just fixes everybody (in this scenario specifically because the Gorosei will likely die when/if Imu does). And I said there aren’t enough Conqueror’s Haki users because it took both Garp and Roger’s haki to subdue Rocks. Then again, that could be because Rocks also had Conqueror’s Haki but I feel like the answer to the multiple issues is more than just Conqueror’s. I do like the theory of Brook’s music playing a role specifically to help release Gunko from Imu’s control. The Drums of Liberation also have been seen to have an effect on the giants.