Couture and Hertl don't have much value as assets.
Couture is a very good, top six, complementary center who can play all situations and has an excellent shot, but who is 34.5, has three years at $8 million, an NTC, and a extensive history of injuries. He's not a fast skater and doesn't drive play, though he is superb at capitalizing on chances created by playdrivers. Given his current injury and already low speed, I think his value is closer to Burns' - a mid-round pick, a middling prospect, and an offsetting depth roster player. Not a chance in hell we get a 1st back for him.
Hertl is a very good, top six, playdriving center, who can play all situations, has a good shot, wins faceoffs, and is a good playmaker. He is 30, has six years at $8.2 million, an NMC, and his own spate of injuries. He is slow and hasn't been driving play as effectively of late. I don't know what his value is, but given how expensive an acquisition he would be for any team, I would be shocked if we got a 1st back - maybe a late 1st with retention, an offsetting high 3rd, and eating a bunch of cap dumps, some with a bit of term - think the Karlsson deal but much less lucrative for us.