Net Admin is an IRCd oper level where Services Root Admin is a Services access level. The 2 are not related at all. Anope doesn't even know what a NetAdmin is.
With Anope, I'm affraid you will have to do a bit of reading of /os help to see who can do what. There is no concrete list of what each can do simply because a module can change it. Example is that /os staff is a Services Oper command, but in less than 5 minutes I can write a module to make it so only Service Root Admins can use it. Not to mention that each module is optional so to be as flexible as possible we have elected to not lay out the help in a static fashon because services it's self is not static, it's rather dynamic to the point that you as the Services Root chooses what commands are availible and by whom, not to mention in the near future, it's going to get even better!

*that was a teaser*
So with that said, get used to consulting the built in help system because:
1> as an oper you should know your services and that's how you get to know them.
2> it's easier use /os help than going to a forum or an IRC channel for the same info.
3> Anope Project is run by volunteers and we may not always be around for you.
4> you become self sufficient.
I can tel you that an easy way to see what the default is to register a temporary nick oper it and do an /os help .. list the commands, then add that nick to the Services Oper list and list the commands (because there will be more of them) ... then add that nick to the services admin list and list the commands (still more commands) .. then finally the rest of the commands are services root.