Knowing that Jes Goodwin puts a lot of thought and work into symbolism, his work with the Eldar and Adeptus Mechanicus are two prime examples, it would seem unusual to have symbols that seem so familiar in the universe mean absolutely nothing, or point us in a direction as a portent of the past and the future.
"So what!", I hear you say. "Who cares if the Leagues of Votann have allied, worked with, had some interaction with the Xenos races of the universe. Well as a Tau fan, personally I don't care - but the Imperium will, which could give you an idea of where this could go. Also symbolism such as that on banners and heraldry usually denotes fealty, something much more significant than just a picnic in the park,
To the left we have the Greater Thurian League - the big kids in the Leagues of Votann - and their symbolism is very like feudal Japanese iconography, which led us to think about an alliance with the Tau. Ignore the lettering that looks like it says "Tau", but the way it's set out to have that very Shogun-esque look to it, much like the Tau and their influences.
To the right we have the Ymyr Conglomerate, which to us looks very clearly Necron aligned. From the sarcophagus shape, to the gold inlay - not only Egyptian-inspired, but very similar to Necron transfer sheets. Not only that, but the Ymyr Conglomerate does sound like a very Necron name, despite Ymir being a character from Norse myth, a direct link to the knot work we see in the place of hieroglyphics. It would be unusual for flash creatures to ally with the Necrons, unless they both had something to gain...
The next two suspected alliances are a little more tenuous, but as Jes Goodwin also did the design work for the world building of these factions it could all align.
The Trans-Hyperian Alliance and the Kronos Hegemony both look Eldar-esque to us, and an alliance with the Eldar could be possible, especially if the Votann have eluded Chaos for so long. The backbanner shape (very common with the Eldar in their original incarnation) is represented here in the Kronos Hegemony (left), but the rest of the linking seems somewhat more tenuous. The Trans-Hyperian Alliance (right) has shapes that could point to Dark Eldar, or frankly the scarab shapes could also point to another Necron ally.
Although not as strong a visual link as the first two, there could be some synergy here, and like the first two, where there's smoke there's fire!
What about the Urani-Surtr Regulates? Well the human lettering could point to a link to the pre-Imperium times, and it could also point to the corporations who would have delved deep into space. Maybe this is based on a mining or shipping corporation that was the progenitor of these group. Maybe they were colonists on a corporate world. The name "Urani" also echoes "Yutani" the corporation in Aliens and Prometheus.
The Warhammer 40K universe is massive, and potentially up to you - but not all things are as they seem and these potential touch points for drama could be great triggers for campaigns!
Thanks for reading - and let us know what you think of this idea.
Not saying it is the intention of the designers at Games Workshop, but it does seem awfully coincidental to have this iconography echo so visibly with these other factions.