It's a constantly evolving game, I'm not entirely convinced by yer picks...
Ruler of the Seas least of all from a budget perspecive, Sea Genie is much less vulnerable to reflect.
But some of those others on the list... Kraulus, Black Dragon, for Silver I think are great choices!
Sea Genie was #78 and #97. I did'nt provide the picks, merely scrapped the data from the usage posts provided by @jacekw for the past 5 seasons. Have a look: https://peakd.com/hive-13323/@jacekw/usagewin-rate-of-monsters-and-summoners-for-each-league-or-season-66
I have seen those reports. I wish DarthGex's tool was still up and running where you got all of that and could sort for ruleset too!
The win rate chart is unsruprisingly a list of legendary monsters!