Paul is on target. I'll just expand on my rationale when I was designing this part of the module, plus list the sources that I used.
CPVA Initial Intervention MG
The CPVA entered the war with a little bit of everything, which made their logistics a nightmare. That is why their Initial Intervention MG are B11. I assumed that the MG which were acquired in the 1930s were mostly gone by 1950, either destroyed in war or worn out beyond repair. So the most common types of LMG in service with the CPVA in 1950 would have the the weapons that were either manufactured in China during the 1940s (the ZB-26 in 7.92 x 57mm), captured from the Imperial Japanese Army (IJA) (Type 11 and Type 96 in 6.5mm and Type 99 in 7.7mm), and supplied by Lend Lease (mostly Canadian-manufactured Bren Mk II in 7.92mm). The LMG counter artwork is for the ZB-26, probably the most common weapon. Using the same logic, the most common MMG/HMG was the Type 24, which was a Chinese-manufactured Maxim design in 7.92 x 57mm. Just as with the German MMG/HMG, the MMG and the HMG are the same weapon, with more ammo for the HMG. The CPVA also used Japanese MMG/HMG in 6.5mm and 7.7mm, and assorted other weapons.
CPVA Soviet-Armed MG
The artwork on the counters represents the standard Soviet MG of the period.
LMG = DP-28 or DPM or Type 53 (Chinese-manufactured DPM)
MMG = SG-43 or SGM or Type 53 (Chinese-manufactured SG-43)
HMG = PM1910
0.50 cal HMG = DShK-38 or DShKM (Chinese-manufactured DShkM was the Type 54, so first entered service after the Korean War)
How difficult was CPVA logistics?
The CPVA was using 7.92 x 57mm (Mauser), 7.62 x 54R mm (Soviet), 6.5mm (Japanese), 7.7mm (Japanese) and smaller amounts of 30-06 (American) and .303 caliber (British) ammunition for rifles and machine guns at the same time.
Kangzhan: Guide to Chinese Ground Forces 1937-45, Leland Ness with Bin Shih, Helion & Company, 2016
Chinese Civil War Armies 1911–49, Philip Jowett, Osprey Publishing, 1997
The Chinese People’s Liberation Army since 1949, Benjamin Lai, Osprey Publishing, 2012
The Communist Chinese Army (DA 30-51), Department of the Army, September 1952