I find the man page documentation about behavior in cases where Exec* commands fail somewhat lacking.

The ExecStart doc kind of hints (in the part where "-" is discussed) what happens if a command line fails and there are multiple command lines, but it'd be good to be explicit about it: does a failure of one ExecStart command line cause the remaining ExecStart command lines to be skipped, or will they run anyway?

For ExecStartPre, ExecStartPost, ExecReload, ExecStop, and ExecStopPost the behavior when there are multiple command lines and one fails is not documented: are the remaining command lines for the same option executed or skipped?  Documenting it in ExecStartPre would be enough because the rest refer to ExecStartPre.

What happens if ExecStartPre fails is not documented - does it cause failure of service startup at that point without executing ExecStart, or does it simply pass through?