I am not telling seeker is worthless. But in a Luxchomp deck, no. First of all, the deck works very well. Four poke turn is more than enough. Imagine each bright look kills a pokemon (Spiritomb or other preparation pokemon). 2 Prize.
Dragon rush with let us say 2 poke turns: 3 prices. Aaron s collection takes out the dead SP Lv.X back and usually, there is at least 2.
Maybe you think that you can use it against Trainer Lock, Hello Dialga G. Plus, it waste you supporter in a turn. More, an Uxie back into the hands or your opponent.
Seeker seems good,but it can be very bad too. As for SPs (Cheapest pokemon cards in the world), poke turn is the best (it is like a old scoop up fused with new super scoop up, and just for SPs).