Right?! Shanks is way too meticulous, careful and thinks of the futur, in long term or bigger or multiple steps for this to be a random decision especially with a Yonko, the WSM, a former Rocks Pirate AND his own former Captains and father figure's beloved rival and friend!
Oda didn't just create Rockstar randomly and give him one of the most important scenes and duties in the series too. No fucking way. Just randomly joins Shanks, an extremely tight knit and cautious crew? Fuck no lol.
Oda has been setting up pieces for the most insane chess gambits for decades now!
Or almost 2 decades ofc!
You get it, thank you! This shit has been driving me crazy for YEARS!