I blame Gygaxs’ pole arm fetish from D&D. Keeps leaking out all over the place.
I was thinking the exact same thing. Specifically Appendix T (yes, I did have to look that up) from Unearthed Arcana. 6 pages (with drawings) about proper
nomenclature of pole arms, with a rambling preamble about maces, morning stars and Authors Who Should Know Better.
Based on his drawings, E.G.G. would have said the Grey Knight picture is holding either a Voulge, a Glaive or a Glaive-Guisarme, likely the latter due to the spike on the back. Several days later he would have finished explaining why the Swiss variant is undoubtedly superior.