Where guard falls on the positional hierarchy depends on a lot of things. A good guard can be dominant, but generally speaking, a guard is not always dominant.
The pertinent question is, do you have control of the opponent? If the person in your guard has broken your grips and made base...no. Contrast this with knee mount, where even if the person on bottom is doing everything right, they're still being dominated until they're not under knee mount.
To wildly overgeneralize, BJJ and SAMBO tend to disagree on this issue.