Hi,
either option you’ve proposed would work fine for what you are trying to accomplish but I would actually do both. with option 2 you will be able to create access profiles and roles and then make them requestable for your end users. Certification campaigns can then be run as needed. AD however can have various capabilities that end users don’t recognize as AD applications. Example: you might have VPN access through AD and users just know it as VPN so you can create an application and make it requestable as VPN. Either way I think you will be able to accomplish your goals.