Update 3-12-21:

The CSGCG now has three types of hammers: The Standard, CMMG, and FGC-9.

Prior to this version, the Standard hammer was taller than the CMMG hammer - this is because I wanted to ensure it would work reliably in every application it was used in.
Since that time, I've been able to develop an FGC-9 specific hammer - removing the need for the standard hammer to be so tall thanks to some tweaks in geometry of the hammer itself.
The documentation may mention that the CMMG hammer is shorter than the standard hammer - please note that this isn't the case any longer. The standard and CMMG hammers are now essentially the same height - they have some slight geometry differences still, which is why both are still included.

Thanks for taking the time to read this update note and understanding the situation - the latest model of the hammers should function better in their specific roles.