My opinion? Yeah, 25 yards with iron sights is difficult, if you're shooting for a small target. With my Remington 121 pump .22LR, I am able to get groups approximately 2" in size, but it's a real strain with (poor, at this range) indoor lighting and old post sights. I've also got fairly poor eye sight, so that factors in as well, but I imagine for someone with good eye sight, it'll still be a challenge.
I figure: those 1" target stickers would be visually the same size as a larger 4" target at 100 yards, and that's a fairly challenging target while standing, in my opinion. not so challenging that you can't hit it fairly consistently (or at least get a decent group), but challenging enough, to be sure.
I should note that I don't shoot from a bench, largely because I don't have a facility with a bench to shoot from.
All my shooting is done standing, prone, or sitting, so being restricted to a standing shot isn't such a setback for me. I was taught by my grandfather growing up that using a support to shoot other than your body will make you a weak shooter with poor form, and if anyone should know, it's him (at the end of his Army career, where he shot on the rifle team exclusively, they asked him to re-up and then compete in the Olympics for the Army - which he turned down because his fiance/my grandmother was pestering on him to get married
).