Difficult to say.
To be clear and be able to understand the situation, let's say this: Imu was able to no-sell the attack from Xebec + Roger + Garp + WB + BM + Rookie Kaido. Completely unfazed and with 0 damages.
DR Rocks and likely HK Harald were are roughly the equivalent of Garp + Roger, maybe HK Harald a little more, but that's it.
The implication Is clear: Imu/Gunko is much stronger than anything we have had as villain so far, and by a very large margin. Kaido + BM would be legit no diff for Imu, not to mention would be DRed and made his slave.
How Loki Is going to fare?
I expect him to be able to fight and hold his own. Even damage Imu, which would be absolutely unheard of (and would put him clearly above the combined 6 of GV).
More idk. Dependsn on how much Oda wants to push on Loki being still injured: