Honestly the fact that the Strawhats are having other storylines in the meanwhile,and even if they perceive that Luffy is losing they keep doing their other things,ruins the tension about Luffy getting almost killed by Imu
Imagine how it would have worked way better as a scene having all the Strawhats apart from Zoro and Sanji getting desperate in front of Imu and Luffy,and then Gaban arriving to save the day!