If I would try to explain the Eel Lobo vs Trend margin, I'd say probably Trend's defense is what has swayed it to his side. It's pretty good, and any opposition of his would need a quality and a really coherent attack to get past that, even if there are weaknesses in the rest of his side.
As for Arnautovic, the situation is not as bad, he could work as a false 9, him and Tadic can exchange positions, so for me it seems like a fluid front 4 that could be greater than the sum of its parts.
Eel Lobo has a pretty good midfield, maybe a better formation would have made it a lot closer in terms of margin, would be my guess.