Would the introduction of Emilie be a net positive for my Arlecchino melt team? If so, should I replace C6 Rosaria (with 100% crit), or C0 Kazuha (1006 EM)?

A subreddit dedicated to Her Ladyship and our Father, Arlecchino aka The Knave: No. 4 of the Fatui Harbingers, the 5-star pyro pole-arm DPS character from Genshin Impact.