Micro-segmentation/ZTNA with Juniper, Fortinet and Aruba

We have a relatively small network (under 5 locations, about 300 switches, access points and firewalls) and leverage Juniper for our core and switch backbone, Fortinet at the edge and Aruba for wireless. We'd like to start moving down the zero-trust/micro segmentation path, but I'm wondering if such a thing is even feasible with very disparate vendor platforms. We are open to switching (no pun intended) if necessary, but are pleased with what we currently have.

• Are there any tools or platforms which could help all of these vendors work in concert without adding ridiculous complexity?
• If you were to consolidate vendors for a specific area, which would you choose? (e.g. replace Juniper with FortiSwitch).