How to manage O365 Group membership through AD Security Groups and/or nested O365 Groups?

I've read some other posts about this issue and there seems to be a core misconseption from MS of how larger organizations utilize Security Groups (Yes, they still have a purpose).  If Microsoft's mindest is 365 groups being used in the cloud for a small organization, there is no reason for linking to security groups.  But larger organizations need security groups on prem, and as other posters have mentioned, there are likely to be many 365 groups with the same members.  Let's pretend we have a group called "accounts_payable".  The group has access to ERP system assets, File servers (yes, not all files moved to SP yet), BI systems and then a 365 group is created for their team.  Then a few other 365 groups are created for projects for that team.  Now we're managing users in multiple groups that all should have the same membership?  This type of mindset simply doesn't work at the enterprise level.  I keep seeing examples like this that make me wonder if 365 is designed for cloud only Small Businesses.

Does anyone have suggestions or examples on how they're managing and tracking their security + 365 groups?  A spreadsheet?  The thought makes me nauseous.