This is largely accurate. We discussed how impactful he weapon would be and felt in general that if we had these massive wings, the odds of us doing another set to do cool combat stuff with was likely further away. Given how many spear users we have and how explored the weapon style is we opted to play up the wings, weaving in the Spear where it made sense.
Plus as others pointed out Set does use his spear pretty heavily, from his attacks to directing his clones. There is an element of contrasting them as they were a dual god release.