Hi Techvin
For DynVPN you could only configure one access-profile because only one can be configured under [edit security dynamic-vpn]. If you try configuring an extra profile, the first one will be overwritten. However, within a single access-profile you can specify more than one authentication method:
"Using the authentication-order statement, you can prioritize the order in which the Junos OS tries the different authentication methods when verifying user access to a router or switch."
Ref: https://www.juniper.net/documentation/en_US/junos/topics/topic-map/junos-os-authentication-order.html
You could configure LDAP and Radius under the same access-profile:
set access profile PROFILE_NAME authentication-order [ ldap radius ]
Ref: https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/access-edit-authentication-order.html
It is important to understand that all users will be checked against the different servers, upon a rejection:
"If an authentication server included in the [authentication-order] statement is not available, or if the authentication is available but returns a reject response, the Junos OS tries the next authentication method included in the authentication-order statement."
Ref: https://www.juniper.net/documentation/en_US/junos/topics/topic-map/junos-os-authentication-order.html
In your case, I am assuming that the Radius user is not configured on the LDAP server hence it will be rejected by the LDAP server and then it will be checked on the Radius and will be accepted.
Hope this helps you; please mark my comment as "Solution" if it applies.