Seems this is what you are talking about:
You can always swap out the card you swapped the last time. The flexibility to play a card as anything you want every cycle is exactly the same as Overlord other than having to line up the thing you're swapping with the card's play.
Here the idiom "you can/could always" is to communicate there is an alternative to a situation given prior, which in this case was this wrong statement:
Swap is just a cantrip if you don't have anything else you want to swap out.
That, I was explaining, is not true. You "always" (as an alternative) have the recourse of using swap on a previously swapped thing; Swap does NOT just become a mere cantrip when there's nothing else new to swap. My use of "always" here is in regards to that recourse being available, not some absolute/literal "always" in the sense of
all requirements to play the card and re-swap the thing you swapped last time will be met. No, I was not saying that at all. As my next sentence notes perfectly clearly (adding emph.): "The flexibility to play
a card as anything you want every cycle is exactly the same as Overlord
other than having to line up the thing you're swapping with the card's play.".
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To just reiterate: Provided you can line it up with
something (anything, including something previously swapped), Swap does what Overlord does.
And yes, I say you miss the point of the card if you don't understand and acknowledge this equivalence to Overlord. It's key to understanding what the card is capable of. Meanwhile, no one misses the remodel variant aspect of Swap as it's just obvious, but if all you do is think about it as a remodeler you aren't getting the point of the card, it's closer to being an Overlord+ that can also improve your deck (with the - of having to line it up)