Silver/Gold Jungler returning to ranked

Hello! like the title suggests, I’m returning to ranked league after about two years. I’ve been absorbing a lot of content, mostly challenger junglers who have their smurf content on YouTube as well as Broken By Concept. Traditionally I’m a Rek’Sai main, though I did have a stint with mord jungle in 2022 that I had a 60+% WR in ranked. Basically through my content consumption, that I do not have the macro knowledge to be able to push early game reksai trades and kills into reliable wins, however I’ve been focusing on just trying a few different champs and basically arrived that my biggest successes in the current season have been through playing champs that can farm up quickly and have big team fight defining ults. Finishing out this season and going into the next I want to establish my main champ, secondary main (in case of pick ban) and my flex champ (in case the rest of my team goes mono AP.) The champs I’m looking at the most is Fiddlesticks, Rumble, Lillia, Mord. For flex AD I’m thinking either Hecarim or I stick with Rek’Sai since I know her kit and pathing inside and out, and I want to dedicate almost all of my brain cells to mastering my first two champs. Any advice would be fantastic, thank you!