I don't particularly expect anything from a full back - any 'kind' can add value to a team if they have the requisite quality.
Being adept at, and extremely partial to, tackling doesn't make Wan Bissaka a first class defender - when I said he doesn't know what he's doing aside from defending one on one, I wasnt talking about his attacking play.
Wan Bissaka has only came into the discussion because of a rumoured £80m asking price for Grealish. Many seem perplexed at the potential valuation and I don't really see why - he's the best player, captain, talisman of the club, is under contract and had an excellent season with Villa only just surviving and with very ambitious owners. They obviously won't want to sell. And reluctant sellers will obviously set a high price. Then look at the general state of the transfer market. Look at how expensive it is buying from other Premier League teams. And yes, look at what United pay for players. £80m on Maguire, £50m for Fernandes, £50m for Fred, £20m for Dalot, £75m for Lukaku, £40m for Matic. It wouldn't be at all surprising if Villa want £80m for Grealish, and even less so if we have shown an interest.