I do data analytics as a day job, and love this post! One of the things I like to do is construct team presets, and am working on my own UI for it. I hope the devs keep this as an option! I know bots and such are controversial, but running scripts to scrape data has been a highlight for me for this game.
Back to presets, so I tend to construct a team at 99 mana, and then think of lower mana replacements much like your first two water deck examples. I would think to make a feature request for the devs to have such presets in game, but I personally would just like more tools and options to customize my UI the way I want instead.