Agreed on that influence part, but he is the one that supposed to be, we can't argue with that.
So thats not a far fetched to say that Shanks is the Roger of next generation which is Mid Gen.
This gets debunked in Elbaf tho imo
In the flashback with Gaban Shanks clearly says "what i wanted to do was just sail around with Buggy and have fun"
So yeah, its true Buggy saw Shanks as the next Roger, and wanted to be his Crewmate/right hand he himself has never that ambition.
Which is also retroactivly true, he never went for the one piece (Roger did) and only does because Luffy is "ready" after 20 years when Luffy is ready, as a test most likely. Shanks doesnt bash in into the battle like Roger and Luffy, he is mediator, he is "just" a yonko and so on i think you get the jist
I dont think there is a Roger > Shanks > Luffy linage imo. Doenst track.
There is a reason we got multiple scenes where people said Luffy reminds them of roger, none of Shanks reminding anyone of Roger