For whatever reason, the narrative that Deryk Engelland was "really good" after Mark Giordano got injured last year has taken root in various areas of the Flames fanbase and mainstream media. I don't know if it's because the expectations were really low for Engelland and therefore anything not resembling total, team-wide disaster in Giordano's absence would be considered a success, but the reality is, it's just not true.
My guess is the correlation of the Flames winning down the stretch with Engelland in a top 4 role is what has given rise to this perception. Unfortunately, the Flames won in spite of Engelland's promotion up the depth chart, not because of it.