I don't think Ankalaev needs his wrestling to beat Jiri. Ankalaev is pretty defensively responsible. He manages distance well and makes good use of feints, hand-fighting, and stance switches to snipe and counter his opponents with fast, straight punches down the pipe while mixing in the occasional looping shot from a weird angle with offbeat timing. He also seems to hit deceptively hard. Never been shown to have a poor chin or questionable cardio. Not to mention he's a ferocious low-kicker.
Given Jiri's tendency to get picked apart by decent boxers and get his lead leg chewed up in fights... I think Ankalaev is a bad match-up for him even in a striking match. The fact that Magomed has a theoretical takedown/clinch threat in his back pocket to fall back on at any given moment is just icing on the cake.