West Ham, Palace, Chelsea, Man Utd, Brighton off the top of my head in addition to the ones you mentioned all have decent back up keepers or ones that they are trying to produce for the future
We don't know how good Karius is though, the last we can judge him on was a pretty useless time at Liverpool and Gillespie is hopeless. At least Dubravka is an average enough Prem keeper
There was talk that we needed to upgrade on Pope this summer anyway
I'm always amazed at how bad attacking teams seem to be trying at breaking down really high defensive lines
We did that really well against Villa but teams seem to really struggle