I'm sure Ten Hag is comfortable right now. Many players will be on holiday for the next 2-3 weeks so it's not as though we are losing any training or integration time with them.
We as supporters are obviously drawn to new signings, but we should also not want our club to on the wrong side of a transfer deal so if playing the long game on the likes of De Jong will allow us to get the best possible terms, which could in turn then positively affect what else we can do in this window, then I see no reason why we can't exercise a little patience.