Is that XenStaff you are using for your guilds page? When I created that, it was for no more than acknowledging staff or contributors. The gibberish is strange, maybe the phrase got messed up. I use it on my wife's site and never had any issues.
The roster program defaults to what you want it to do. If you do not select any menu items, the groups are displayed as the links in the menu bar. If you select any menu item(s), it has priority over the group links and replaces them. This is done to allow you to create a new members tab, for example, where you can display today's birthdays, gender, recent activity, etc. consisting of members belonging to the groups you selected.
The roster add-on allows admins to create numerous tabs, each with a unique pre-defined (by you) route, and/or create a number of tabs using the same route name. For example, you can create 3 different guild tabs, each containing of a guild group that is displayable to that group only (if you choose), consisting of links from custom fields (if you choose). And at the same time create a Contributors/Sponsors/Staff/or whatever tabs.
I will be using it for guilds, and as well have another tab that allows visitors to list members that have created a character, by different classes: Fighters, Clerics, Thieves, etc. The way Guilds that will be set up with my forum will operate a little different though. Guild links will only be displayed to those members whose characters have a skill level high enough to see them, or have discovered them by adventuring. The displaying of guild members will be handled the same way. This way one guild may be able to plant "moles" in other guilds.
I should add here that I removed the option to allow the roster program to add links to the Members tab. I seen no point to this as you can re-assign the members route prefix to the roster add-on, to be used by you, or not used (either way, the original Members Tab is removed).