We got family portraits done a couple of years ago, and I dressed my 3 girls in the same white shirt, and the 2 older ones had matching skirts. I think the photos are beautiful, and don't think myself a weirdo for having dressed them that way.
My older 2 have a few items the same, but they tend not to wear them at the same time.
I don't think you or anyone else is a weirdo for doing it it just isn't my thing

I dunno about the individuality thing. It's a bit of yes and a bit of no. If I let my eldest DD express her individuality through clothing I shudder at the thought of what she would wear I'd have a little Kath or Kim on my hands LOL. Seriously though, its much the same as baby names - I might hate what someone has called their child and would never use the name myself but they love it so whats the harm kwim? I often get asked if my two are twins as it is (I have no idea why, they don't look all that similar) let alone if I dressed them the same and I want them to be comfortable in what they are wearing and not feel forced to wear something the same as their sister purely because that's what I want them to wear. I don't like being told what to wear so why should they?