My take on this article:
You are allowed to use more than one account. I have all of them.
For foreign currency, use Revolut up to the £1000/month limit,
https://www.telegraph.co.uk/money/banking/current-accounts/revolut-monzo-starling-which-best-online-bank/
Revolut vs Monzo vs Starling: Which is the best online bank?

Telegraph Money reveals its verdict on which of the big three comes out on top

The Telegraph
if you need more, then either Trading 212, or use Revolut to add money to your foreign currency account using a Debit card from another account that gives you Mastercard Rate, such as Chase, or Virgin Money.
If you want to make international bank payments in a currency other than Euros, then HSBC Global money is good, but use Trading 212 to get the money into it because HSBC's exchange rates are not good.
For cash withdrawals, Chase or Virgin Money are best.
Trading 212 gives you interest on some currency balances. Funding Euros from Revolut works fine, but for other currencies Revolut has pretty high charges, so it would generally be better to take the slightly worse exchange rate they offer.