Funny, I’m not sure either. I suppose it depends on what lenders look at more favourable and I suppose they vary.
I’ve just opened up an Amex (£5700 limit), HSBC (£3000 limit) to go alongside a Vanquis (£1500 limit) and a Barclaycard (£1200 limit). I’ve only had the last two for about a year, so not sure whether it’d be wise to close the Vanquis in particular which I’ll now never really use. Or whether it’s worth keeping open given it’s the longest running credit card I have.