I have a series of scripts that get called in an explicit order by another
script1 = str(sys.path) + "\\script1.py"
Subprocesses takes a list of arguments, which it then turns into a command it executes.
subprocess.call(["Python", script1, 'arg1', 'arg2'])
subprocess.call, all the parts of its list are arguments. You just happen to be specifying "Python" and script1, but to subprocess, both are just other arguments.
There is a lot more reading on the documentation for subprocess which I would recommend looking over.