Jp video shows blu strategy and it takes 2min56sec total including 15 sec loading zone and buffs. So its not BLU strategy that is slow, but some people not doing it optimally. He soloed VD on BLU in 15 min.
The reason why people has been reporting much slower run than the JP video is because their setup was not identical to JP setup.
In the video, they used:
1) Indi frailty, geo malaise, entrust Indi acumen. So all 3 bubbles should be DD bubbles.
It seems that everybody that needed 7+ min used defensive bubbles, which is probably not a requirement, and kill speed will slow down.
geo malaise/vex/attunement
Edit: GEO used Malaise/Acumen/Entrust Attunement. Cor/bard buffs are the same you would use for melee. No need to use light carols.
2) They skipped cor in their set-up and had a MNK hitting really hard on the boss. By the time adds were done boss were at 30% HP already. Having the DD take down significant amount of HP on boss before cleves are done is crucial for fast runs.
I think cor is still a good choice for this slot with rolls, but frailty can't be skipped because DD needs it.
3) They finished buffing in less than 1 min. You would be surprised at how many BRDs out there needs more than 1 min to finish buffs.
4) Daybreak dispelga is extremely fast when it comes to removing shell on all mobs. If shell isn't removed immediately cleave speed will slow down.