The problem with these online scouts is that they all like the same type of player; they all have massive boners for undersized danglers/flashy players. Look at guys like Aron Kiviharju [ranked #44 vs drafted #122], Justin Poirier [ranked #65 vs drafted #156], Clarke Caswell [ranked #79 vs drafted #141], Alex Zetterberg [ranked #84 vs undrafted], and Christian Humphreys [ranked #87 vs drafted #215].
There examples of the opposite as well. Bigger, athletic, physical players who don't have a ton of counting stats are ranked lower. Obviously Eliasson is one, but there's also AJ Spellacy [ranked #111 vs drafted #72], Colin Ralph [ranked #96 vs drafted #48], Ilya Protas [ranked #134 vs drafted #75], Ethan Procyszyn [ranked #122 vs drafted #68].
I also find that the online scouts are less inclined to rank 2nd and 3rd year eligible players.
So the Senators are always going to be hard done by these online scouts. They target big, athletic, physical players almost exclusively and they tend to take overage players more than other clubs.
None of this is to say that Gabriel Eliasson was a good pick - I don't know that. If it were up to me he wouldn't have been the selection. However, he was ranked 55th on McKenzie's list which is the only list that has input from people that actually do the job. I suspect that had Ottawa not taken him he'd have gone off the board in the next dozen or so picks regardless.
Sometimes the strategy works and sometimes it doesn't, but one thing is for sure - the Sens go into the draft to get the guys they want with no considerations to how anybody else will view it.