Kathelia's team probably had the easiest time working together in battle chess. Isolde and Dandy weren't trying to disagree with her strategy, and they all wanted the same outcome of Eupheria's games, so it made sense to work together. Since Kathelia knew that there was randomness added by Eupheria and that each of the other teams had one of her sisters, she expected them to fight a lot, and to fall back on their strengths. That made things easy because they were predictable. Eska would settle on a bishop early to strike across the board, Azora would use her princess aggressively. Kathelia didn't like the idea of fighting Alina or Adila (or other Adila, she wasn't really sure about that one), but she had Dandy stay in reserve for when fluffy Adila showed up because that was a good matchup. There was also something to using a horse as a knight that did actually have the right feel, though she didn't push Dandy too hard on that front. Isolde would be a good match for Alina, especially on a smaller piece if they could defend a simple pawn when Alina came out so none of her lights would be in play. 

Really, with both of Kathelia's teammates, it was mainly a question of motivation, rather than strategy. Isolde was obviously depressed and Dandy seemed like she was dealing with some things (in fairness to her, it seemed like what fluffy Adila had said had really been a big deal) so Kathelia had to do a lot of work to get them to pay attention and give the game their focus. A lot of "we're the team thatth betht pothithioned to wisth everyone elth out of here!" and some pats and hugs. 

But at the end of the day, it was a simple strategy that was best here. Play to their strengths, look for good matchups. In a complex game with many sides and lots of randomness, simple was often the best strategy. This wasn't a pair of expert chess masters trying to out-think and out-gambit one another, it was a scattered group of teams who probably weren't going to agree and would fall back on their own first order strategies. Kathelia was ready! 

[Sense with Despair: 5, 5, 5, +0=10]