let's have a container with profiles of version v1.

It is possible to try to add a profile of version v2 to this container and it obviously doesn't work because it doesn't make sense

2 cases:
1. trying to add a v2 profile named same as a profile in v1 adds the v1 profile to the container. (e.g. instead of v2 "default" profile v1 "default" profile is added )
2. trying to add a v2 profile with unique name that isn't in v1 profiles set doesn't add anything to the container (without any warning)

How to add a profile this way:
Fabric - Profiles - select a version - select a profile - click Assign button - select a container - click different Assign button

I would say a user shouldn't be allowed to select a container with different profiles version that he/she want to assign.