We’re actually going to give you two hints today. The first is this: while it’s true that Merge-CsLegacyTopology is the only one of the four cmdlets that uses Merge as its verb, well, that wasn’t really what we had in mind. (That would be a bit too easy.) And the second hint is this:
You don't need to be helped any longer. You've always had the power to go back to Kansas. Or at least back to Office Communications Server 2007 R2.
And, no, based on that second hint we don’t think you need a third hint as well. You should be able to figure it out without too much trouble.