Nice list. We have very similar picks!
Fire - Tenyii Striker, Grum Flameblade, Forgotten One
Water - Deeplurker, Wave Brood, Baakjira
Earth - Regal Peryton, Mycelic Slipspawn, Goblin Psychic
Grum is a shoo in when I get my favorite ruleset Reverse Speed and fire is available.
For Earth I don't have Queen Mycelia and I don't rent and I've only used it when I joined Zensports tourney before and rented it so I can't say it's a favorite. I do wish I get to pull it. Peryton is my most favorite non legendary card and it's a toss up between it and Psychic which I use more. Grund I do like a lot but I find there are less situations I'd have a use for him than these two.