Ok, I've been playing Gwent for more than half a year now, I reached Pro in two previous seasons (without playing Renfri!), so I consider myself quite an experienced player.
But I still haven't found the point of Ardal aep Dahy in Nilfgaard, even in Tactics deck. Normally, you have like 8-9 tactics in your deck, so you can move a unit with 8-9 power at most to their hand. So it is not enough to "reset" a meaty engine, because they grow to 10+ points over the course of the round (maybe a slow engine like Garkain). It also doesn't make any sense to move anything with Deploy abilities. I can see a point of moving the likes of Knickers, Roach or Tuirseach Skirmisher (this one can backfire, if your oppo has Birna or Koral in hand, lol), but that's it. Even more – you are not guaranteed to draw card of your choice.
After this slander – how to play this card correctly and not make it circumstantial? Wouldn't it be better to change his ability to "… then draw the highest-provision tactic from your deck". It is a 12p card after all…
Source: https://www.reddit.com/r/gwent/comments/wmgqtc/how_to_use_ardal_correctly/