Thanks in advance,
Best answer by Attilla
With EVPN you can implement L2VNIs. It has various enhancements over VPLS, because you don't rely on dataplane learning. In your case you can use that to for the firewall cluster-links or any other streched L2 domains. You also have the possibility to create L3VNIs which can replace the L3VPNs that you have on your core and distribution layers, unless you have specific traffic engineering requirements.
We recently released a new book that explains EVPN and the aforementioned technologies:
Given the time of your posts, I assume you're based in Europe. Since I'm responsible for this region, I'd be happy to exchange some e-mails, messages on Slack (https://slack.cumulusnetworks.com) or jump on a call to discuss more details around your environment.