I expected worse. Those 3 aren't that bad of plays. Neither are true WR1's but I think you can get at least average numbers week-to-week with these 3, especially Robinson and Landry who are both #1 receivers in their offense. That's who I would start.
Landry is Tannehill's most trusted receiver and one of the most exciting receivers to watch in the league, imo. Despite the lack of RAC ability to put up insane scores on chunk plays, the offense is throwing 40+ times and will get 10+ targets a game. I think you can count on 6+ catches, 75+ yards and at least a few targets in the red zone each week.
Robinson is the next best play, imo. A lot of that has to do with Blake Bortles taking the next step in development, at least from what I've seen. Robinson also has the play making ability to put up huge numbers. I don't know why there's such a big difference between week 1 and week 2 for him, but I think he's closer to what he showed against the dolphins.