@shad Well since this is about tactica... (lol) I will exclude waifu factor and aim for usability only.
With your team, just like Wutan, I would go for crit team since you have two powerful crit girls in your team.
Shiro-chan, and Wolf Berry are both powerful. Especially Shiro-chan as cornerstone for powerful crit team.
You have many options to fill the 3 slots. This is my personal set up.
Shiro-chan, Wolf Berry, Loquat, Streptocarpus, and Purslane (yet again)
This set up gives 85% crit chance (capped at 80), 130% crit damage, 1.4x skill activation with extra 2x if Detective-chan got hit (use provocation to archive this easily, 2 provocations in the same team will make the target randomly attack only the 2 targets) , Purslane can act as tanker just as good as dishing damage. 3 sweeper and 2 finisher. Note however... Only detective-chan has sizable boobs, the rest 4 are complete pettanko. You can remove Purslane for Either Kuro-chan or Aizoon for 1.6x skill boost and 10% less crit damage though. Higher damage, but no tanker.