I have several, waiting on parts for another. 556, 308, and waiting on a 300blk DSG upper. First AR I ever shot was a Colt SP1, hated the damn thing. Friend used to run WD40 as lube though so it felt like hell. Kinda funny the turn I took.
I have 2 - a high end one (waiting on a can for it) and a budget build. So, yeah, they are set up differently. Expensive one has a Leupold optic, budget has an open red dot sight. Both have Magpul BUIS. Milspec other stuff, just different brand (and cost) for stock, rail, etc.
I have an ar15 carbine and an AR10 carbine. I'm in the process of setting them up as identical as they can be. Probably down to the same scope on them too. My two hi-cap 1911 style pistols are pretty much the same way. Identical except for caliber.
I currently have several in different forms and calibers. Calibers would include 5.7, 9mm, 5.56, 300blk , 6.5 grendel, 6.8 spc , .308, .204 , 458 socom. I have the same caliber in a few versions, 24" heavy and 16" carbine. each gun is a little differnt, the 24" guns are very similar, the 16" carbines are all pretty simliar and the two shortys are very similar. The caliber and length kind of dictate its role and how its set up. for instance the rra 16 458 socom is set up to hunt, the radical firearms 10.5 458 socom is a duty weapon. I like to pair guns, so There is a 24" heavy 6.8 and a 16" carbine that go out together. the only two not paired are the .204 and the 6.5 grendel. Everything else has a mate in the same caliber but different role.
I have the following in 5.56...
7.5" SBR
10.5" pistol (waiting for stamp)
11.5" suppressed SBR
Three 16" ARs
An 18" SPR
Currently building an 18" AR in .308 and considering selling one or two of the 16" builds. They each have a specific purpose but my favorite is the suppressed SBR, soon followed by the SPR.
You only have a problem if you're counting what's "hers" as what's yours! If not, carry on... And no, I don't believe Que's claim that they multiply when no one's looking! LOL, and for the record my first response to the OP was "Who doesn't" but then there's Jagee...