well it depends. Sancho was, like Lamptey, bought as a teenager from a top 6 club (and then sold for a ridiculous profit!). Probably the Albion model here. (see southampton and Livramento also..take a punt but buy the player outright and promise em game time (see Sarmiento here too!)
Nelson...
Dan Ashworth on incoming loans in a recent interview in the Athletic via https://theathletic.co.uk/2884020/2021/10/12/ashworth-on-brighton-loans-the-three-types-player-wishes-and-logic-behind-sima-and-andone-moves/