@SH_MM If I had to guess, maybe it's kind of like why Uranium alloys won out in the US for penetrators? Abundance and ease of manufacturing. Staballoys are easier to extrude and turn on a lathe than Tungsten alloys, they can also be drawn and cold rolled with less difficulty. WC and WHAs are often both sintered into a near-net shape because of the difficulty of machining them. Comparing between Oak Ridge's guide to machining depleted uranium and Midwest Tungsten Service's machining guide for their MT series heavy alloys, with a density of 17 g/cm3, the tungsten alloy requires a higher spindle speed, a slower feed rate and a slightly shallower depth of cut on roughing. In the worst case for both metals (slowest spindle speed, slowest feed rate, shallowest cut depth), you can turn tungsten at about half the rate of Uranium on a lathe.
1" Uranium bar Roughing: 573 RPM, 0.012"/rev feed, 0.050" cut depth = 1.080 in3/min metal removal rate
1" WHA bar Roughing: 764 RPM, 0.008"/rev feed, 0.030" cut depth = 0.576 in3/min metal removal
WHA lets you go significantly faster than uranium on finishing however, again comparing the worst case scenarios for both metals we get
1" Uranium bar Finishing: 1050.423 RPM, 0.002"/rev feed, 0.002" cut depth=0.013 in3/min metal removal
1" WHA bar Finishing: 954.930 RPM, 0.004"/rev feed, 0.010" cut depth=0.120 in3/min metal removal
This is why WHA penetrators are manufactured as close to the finished shape as possible while Uranium penetrators can afford to be further off from the complete shape.
Tungsten Carbide is an absolute bitch to machine too, requiring specialized inserts like Polycrystalline Cubic Boron Nitride and cutting rates during roughing that approach the finishing speeds of Uranium
There is also another difference between the two materials that's worth noting, how they interact with the actual cutting tool. Uranium is frequently compared to austenitic steel in Oak Ridge's literature, described as being susceptible to work hardening and built up edges. Tungsten on the other hand varies between class 4 alloys which behave like a highly abrasive version of grey iron with a risk of chip hammering, to the less dense class 1 and class 2 alloys whose behavior is closer to Uranium.