Multiple Github accounts based on user name instead of host

I saw the suggestion to work with multiple Github accounts is to create a SSH config with multiple entries like so:

Host aliasUser1
	HostName github.com
	User git
	IdentityFile ~/.ssh/user1

Host aliasUser2
	HostName github.com
	User git
	IdentityFile ~/.ssh/user2

This will allow me to run commands like so:

git clone aliasUser1:user1/repo.git
git clone aliasUser2:user2/repo.git

But I prefer to have a configuration that will allow me to run the commands as usual and make the differentiation based on the org/ user name, meaning:
git clone git@github.com:user1/repo.git -> will use user1 key
git clone git@github.com:user2/repo.git -> will use user2 key

is this configuration possible?

I'm not sure what to try currently

Yes, you can do this, you have to do a little finagling. Git's got a general-enough url rewriting config, url.<realprefix>.insteadof.

git config url.workme:user1/.insteadof git@github.com:user1/

and from then on Git will rewrite the git@github.com:user1/ prefix to workme:user1/ and then recognize the result as (still) using ssh; you need to configure your ssh to put the real connection data back:

host workme
  hostname github.com
  user git
  identityfile ~/.ssh/user1.pub