First, please take a look at: What to look for in a server rack?
These days, racks are pretty compatible and server rails solutions to accommodate 4-post square-hole racks are flexible.
A mistake people make with some rack enclosures is not adjusting the depth (if adjustable) before mounting their gear. If I'm building out a new co-location site using adjustable rack depth, it's the first thing I modify.
When it comes to your specific hardware's rail kits, make sure you're using them correctly. If unsure, pull the online instructions/documentation for the server and check the implementation guidelines. Your comment on "screw holes" not matching probably means that the rails are of the "tool-less" type and aren't meant to be screwed in. Also double-check your rack-unit enumeration (the holes are NOT equally spaced). As for the fixed-rails on the IBM x3250 M2, they are not telescoping rails. You're not supposed to be able to extend the server with them. It's just a shelf.
So there are two issues. If using a non-IBM rack, there are clipnuts/cagenuts that you'll need in order to prevent the twisting you mentioned. If you find that the stock rail kits for the servers you have are just not suitable, you can just go 3rd party... I would suggest using the specific x3250 M2 kit from Racksolutions.
