> I'd say vi/vim needs to be put under /etc/alternatives

No, because that's system-wide. 
Vi vs Vim is a personal choice. Also alternatives is for supporting multiple versions. Say v8.02 versus v9.1 of 'vim' on a system, one being in /usr/bin and the other in /usr/local/bin just as an example. And the sysadmin choosing (for whatever good reason) to preference the v9 software over the v8.