Groomsmen attire

One of my groomsmen is fairly well-off financially, while the other four struggle in that area. In light of this, I'm being more flexible with my requests for their attire at our wedding.

I'm insisting they rent a vest ($25) and tie ($5) from Men's Warehouse in the colors I picked for them, but I'm not requiring them to rent the same suit. Instead, I'm encouraging them to consider wearing their own suit separates as long as the slacks and optional jackets are solid black and the button front shirts are white.

I find myself occasionally worrying (mostly in my Maid of Honor's voice) that "the blacks won't match" but then I remind myself that it's the relationships we have with these people which is really important so what they're wearing is no longer a concern.

Has anyone else taken a similar route with their groomsmen?