From a purely neutral prospective, I don't think you can judge it on one meeting last time out. I'm literally looking at last year's meeting for Berwick, and Etheridge scored 5 points from 6 riders. The year before? 1 point from 4 rides.
If you look at the bigger picture, Gusts was competing in the Grand Prix Challenge at the weekend, and Knudsen finished third in Danish Championship. Etheridge and Hagon don't offer that sort of pedigree.
I don't think there is any real doubt Oxford are weakened. In my opinion, a full strength Oxford side has to be one the strongest in the league, but how often have they actually been full strength? They've been weakened all season (which is partly their own doing, and partly down to injuries), so it's pretty much a normal strength Oxford lineup if you think like that.