Coyle's regular season ppg ave is around .51
Lindholm's regular season ppg ave is around .68
But let's assume your discussion points are an accurate assessment of Coyle's ability ... then there should be no problem or drop off of his new found production by having him carry another line apart from Marchand.
I don't have anything against Coyle I think he is a valuable player for what he brings to the team. But I do think pairing him with Marchand is stifling Marchand's production while enhancing Coyle's production.
I think both players could bring more overall benefit to the team success apart than they do paired together ... especially now that we have options. Last year we didn’t have these options, they were paired out of necessity.
The difference in their career production is PP time.
And yes, if you put Coyle back at 3c (without Marchand) his even strength production would be about the same. He scored 44 even strength points with Marchand last year, and he scored 40 even strength points the year before without Marchand. Again, the biggest uptick in his production last year was from special teams.
You're also saying Coyle brings Marchand down, but Marchand had 67 points with Coyle and 67 points the year before, without Coyle. To be more specific, he had 37 even strength points with Coyle and 37 even strength points the year before, without Coyle.