How not to be a mentor

[Kohashi]

I will also say that I know from experience people in this game are notoriously averse to advice and feedback, here's a situation that happened not too long ago:

I was leveling GNB, and got Akadaemia Anyder on roulette, party was me, an AST, and two DNC, halfway into the last pull, the Healer DCs, and we wait a bit for them, the entire time, the DNC had Dance Partnered each other, and since I main DNC and know the ins and outs of the job pretty well, I bring it up, I forget the exact words but I remember the tone, so paraphrased "By the way, you shouldn't Dance Partner another DNC, the buff doesn't stack with itself even from different sources, so if there are two DNC in a dungeon, it's best to Partner the Tank and Healer so the buff at least is going somewhere.".

The perfect example of a terrible advice. Since I have also main-ed DNC for a while now, allow me to teach you further.

The quote is directly taken from the balance discord since it discusses in depth each point.

Do dancer buffs stack? Should I partner another dancer? Do buffs apply to pets?
Standard Finish:
The standard finish buffs will stack if the partner icons appear different. This means that if two dancers partner each other, their buffs will stack.
The standard finish buffs will not stack if the partner icons are the same. This means that a player who has been partnered by multiple dancers will only receive one buff.

Technical Finish:
The damage buff will not stack, and subsequent techs will simply refresh the buff.
The esprit buff will stack, meaning that a dancer who has their technical step overwritten by another dancer will still receive increased esprit for the full duration.

Devilment:
The buff will not stack, and subsequent devilments will simply refresh the buff.

Pets:
All dancer buffs apply to pets/summons.

In conclusion:
For 4 man dungeons with two dancers, unless the other dancer is severely underperforming, you should partner the other dancer.
In content with multiple dancers, you should ideally try to stagger technical window timings so that you do not overwrite each others buffs.