ESA can get a low cost, reusable version of the Ariane 6 just by adding a second Vulcain to the Ariane 5.
Moveover, without needing the solid side boosters, this can be used to finally give Europe an independent manned spaceflight capability.
Multi-Vulcain Ariane 6.
https://exoscientist.blogspot.com/2018/02/multi-vulcain-ariane-6.html
Bob Clark