In rhetoric no, in practical outcome, yes. The people at the top of all of the major parties are largely interchangeable these days. That’s why someone like Corbyn (who isn’t especially extreme or unusual) has created such a shock-wave and why people like Farage and Johnson can establish such stand-out profiles on the basis of very little real content, just a little show of being a bit different.
The Lib Dems, Greens, SNP and UKIP have all had great influence on national government in various ways without (and generally without being capable of) winning any UK general elections. Part of the problem here is the assumption that winning the election is the be-all and end-all with how you do it and what you do when you get there being very much secondary (if considered at all).
Definitely not a natural, especially in the polished, spin-doctor managed style of the day but I think the Labour party could have made his leadership work if he had the right team around him in support. The reason Corbyn has failed is because he opponents within the party deliberately manufactured his failure. Their sole concern seems to be them winning a general election. Their party, it’s policies, it’s members, the country and the voters don’t appear to be of any concern what so ever. It’s far from a unique attitude in modern politics, it’s just so blatant in the recent Labour leadership dispute.