This may seem super obvious for some people, but I've actually just discovered this for myself and I think documentation doesn't make this super easy to know. This discovery solved some of my woes with configuring my ssh client.

Here's a motto that you should keep in mind when modifying your ssh_config file:

In ssh_config, specific comes first and generic last.

OpenSSH tends to parse the ssh_config file from top to bottom, and by doing so, as soon as you set an option other blocks that might match for the same host further down won't be able to set that same option again. In that sense, having wildcard blocks at the end of the file (or at least after all other hosts that it can match) makes sense since such a block will set the option for all matching hosts only if it hasn't already been set above.