Not at all.
This is how I look at it: A peg is something to hang something else on, like a peg in real life where you hang a coat. It’s simple, straightforward. I rarely use basic pegs, but when I do they’re for single, one-off associations (e.g., reminding me that I parked at B5). I would never use one of these simple pegs in a memory palace; there’s no point. In a memory palace, the location is the trigger that helps you recall the information; you don’t need any pegs. (One exception: Sometimes you will want to be able to recall that a particular item was, say, the 72nd one; for that, you’d need to associate a peg.)
The Major system (like the Dominic system variation) is a way of converting numbers to images. I use the Major system within a memory palace when I need to recall specific numbers associated with my images—not the order of the information but numbers related to it: dates, figures, pi, etc.
If the information I’m memorizing has no numbers associated with it at all—like my list of U.S. presidents (since my focus was on the names, not the years they served)—neither pegs nor Major are involved. Instead, my memory palace simply contains memorable images—usually puns or word-associations related to the people involved—placed at specific locations.
Of course, neither pegs nor Major—nor any other memory technique—requires the use of a memory palace or a location-based system. Using locations—whether contained within a “palace” or spread out along a “journey”—is a technique unto itself.