Marketplace assets never align correctly

This might seem basic, but the majority of the assets I have from the marketplace that include things like walls never allign correctly unless the griud is disabled and I tweek the size perfectly by hand each time, which is extremely slow going. I feel like this shouldn't have to be the case, but I can't work out for to make it so these pieces come out at a correct size to just drop and clip together, like they say they can be used. Is there some setting I missed?

Are the assets from the same creator or separate creators? If they are the same creator then you might want to drop them a pm about it. If they are separate creators then there is not much to be done as each creator has their own standards.