You can specify that individual services belong to service groups, and then in the registry (for each service), you can place a ServiceGroupOrder key - but this is pretty extreme.
If you just want to make sure one service starts before another, use a DependsOnService key, and specify the other service first.
Check TechNet (technet.microsoft.com) online, search on ServiceGroupOrder and DependsOnService - you'll find just about anything you need...