Last season Campbell admitted to having a mental block when his play suffered for 6 weeks. He was putting too much pressure on himself.
https://www.sportsnet.ca/nhl/article...ple-leafs-net/
Oilers fans and media legitimately think Campbell plus a full season with Woodcroft makes them true contenders. When, not if, when his play falters and the pressure mounts from fans and media alike, he'll crumble.
Additionally, without the puck-handling ability of Mike Smith, the Oilers defence will have to retrieve more pucks. Even Koskinen handled the puck often as the Oilers defense had the goalie collecting dump-ins and making the first outlet to the corner, hash marks, or blue line. With Campbell they won't have that ability as his puck handling is average at best, so an already weak defense will he forced to work harder to collect pucks and get them put of there zone.
So a weak defense that's going to spend more time in their zone, coupled with a goalie that buckles under pressure, and by January Campbell is going to be public enemy #1 in Edmonton.