The Watchers, Voidborn and Iceborn

It seems that the Watchers are shaping up to be the greater scope villains of LOL with the revelation that they are also the masters of the Voidborn. But some people are wondering about the seeming discrepancy between previously established Watcher lore and their ties with the Iceborn, and the new information about their connection to the Void. Why would they have two seemingly unrelated powers under their command? Well, I'm not brushed up on the timeline of the LOL, of whether which came first, but if my direct approach of a monstrous army was pushed back and failed to bring home the goods, then I would try a more insidious approach to conquering the world. Make it so no one suspected that I'm the same guy, avoid the attention of those who defeated me last time. Start anew, work in the shadows, corrupt the locals into fighting for me instead of giving them a common enemy. Hence the Iceborn.

The Voidborn and Iceborn are merely different tools, I think. One can use wildly different tools to accomplish the same task. If a human can use different tools to make a house, why can't eldritch beings do the same?