ASA - number of crypto maps per interface
On a Cisco ASA device, you can assign only one crypto map set to an interface. If multiple crypto map entries have the same map name but a different sequence number, they are part of the same set and are all applied to the interface. The ASA evaluates the crypto map entry with the lowest sequence number first.
If you attempt to assign a different crypto map to an interface, it overwrites the previously configured one.
Links:
https://forum.networklessons.com/t/cisco-asa-site-to-site-ikev2-ipsec-vpn/829/71?u=lagapides