NullWire wrote:I think the Arachnotron doesn't need to be replaced by the Gore nest, only the Pain Elemental
Well, don't forget that you can choose to not replace Arachnotrons. It's better when the player have control about it. For example, I like to play only with the original Doom 4 monsters. For me, It feels more faithful and enhances the D4 experience, so I disable Arachnotrons and Pain Elementals by default. But other people may like to play with them, so they can choose what fits them best.
Besides, the way how Arachnotrons are placed on maps tends to work really well with Gore Nests (judging from my experience).