Of course a thana user would switch to an Incantation-carded weapon when their opponent switches to skolls, What Perishable was saying is that in this situation, where you have ultimately negated the effects of Thanatos by using skolls, is it's a more "fair" playing field.
If you are still having problems dueling against Incantation Samurai wielding players, then it obviously isn't a problem with the existence or availability of Thanatos cards.
The idea of Skoll cards is to force the player to switch off their Thanatos weapons. When you say, "Then you put on Incantation Samurai cards," it's ridiculous, since you're using Incantation Samurai cards too, so I don't get it. It's pretty much even steven from there.