I mean, Dier isn't even much of a loss is he? He got hyped last season and even then I didn't think he was particularly special, and this season Wanyama has impressed in midfield and Toby and Vertonghen have had the centre back positions locked down? I thought he'd played a lot less than last season but after checking wiki he's only played ten fewer games this season, so maybe he'd be a bigger miss than I'd thought.
Previously rumours have suggested that United would be looking to spend £40m on him, if I were Spurs I'd bite their hands off. Similarly with Walker. Trippier already looks to have the faith of the manager and seems to fit their system well. The one they should try hardest to keep is Rose imo.
Edit: @Cristo I would think that their options would be the Manchester clubs, City for the two full backs and United for Dier. Despite Spurs being better atm you can totally see why a player would take the Manc money and still feel it's pretty likely they'll taste big success there before Spurs.