These two players are just unsatisfactory at suppressing shots against. It's not because they're individually bad players - both are decent #4-5s but as a duo you've got Wideman who's slow and has mediocre positioning, and Russell whose positioning and speed are good but whose size limits his effectiveness (but you can see from his fenwick against that his shotblocking makes him an NHL-calibur defender). As a pairing they lose one-on-one battles to pucks and end up spending way more time than they need to hemmed into the opponent's zone. They're good enough to not be a liability, but not good enough to be the strength people assume they are.
They had a strong year, and somehow the Flames kept on chugging even when they got upgraded to top pairing competition, but don't let that confuse you into thinking they're a top-shelf middle pairing. They should be upgraded if the Flames have championship aspirations. Giving Russell a partner who is better at shot suppression has shown good results, like when he's been paired with Brodie. But finding a good RHD to pair with him isn't easy or cheap.
From OKG at HF, really makes you think