You've only got to look at other parts of that poll to see that, while hardly 'rent a mob', the result is completely reversed among longer standing members, while for the most recent members it's 86-14 for Corbyn
I'll give you an example of the sheer head in the sand lunacy of the brave new Labour membership: s friend of mine belongs to the Labour Party in N Ireland. Even there the party has been inundated by people who think the sun shines out of Jeremy's allotment. When challenged along the lines of 'you do realise don't you that your hero is dead against the party putting up candidates in NI don't you?' the reply is simply: 'oh he'll change his mind on that' despite the fact there's precious little evidence Corbyn has ever changed his mind on anything. Actually I suspect they don't really care as long as they can go to meetings and on endless demos