Let's take Ghoul first. Who?. Well if you didn't know about the card just check the description: 1 power… Hmm… Consume a bronze allied unit from GY. Okk so the best case scenario is to consume a griffin, ok. Just need to play the griffin first or discard it with Keklerith. Bad value to begin with, if you are not playing Swarm to kill a 1 point drone. So after all that setup which usually requires a round to obtain (griffin is in GY) you get a wonderful 10 points. Lul.
Now Spotter, has armor, can see the top 3 cards, boost is ready to use whenever you please (of course if not locked… Lol imagine locking a Spotter when you can Slave drive it), and on top of that is also 4 power. C'mon guys what are we talking here?
Of course Ghoul could potentially be a good card in thrive decks… That's it, only in thrive decks, and even so it does not ever see play in top ranks? Why? Because it is just trash. Rant over.
Source: https://www.reddit.com/r/gwent/comments/y095px/how_the_heck_are_ghoul_and_spotter_both_5/