Now, odds are, these didn't all actually share the same newsstand space at the exact same time, but I think it is fairly indicative of what a child would've seen in August/September 1961. I've pulled a number of covers from that time period, but I'm sure I've missed quite a few that also came out at that time.
Looking at this grouping in hindsight, I think it's phenomenal that Fantastic Four sold at all. I count no less than 14 covers that feature some kind of giant monster theme. Even Pep here features some space aliens! Granted, Jack Kirby's cover to FF #1 seems to be the most inspired of the monster covers, but even then he's competing with himself on the various monster books that he also drew at the same time: Tales to Astonish, Amazing Adventures, etc.