The Texans have 70 Mil in cap space for 2018, and with some obvious cuts (Cushing) they will have 80+ next year. They gave up next year's first to get Watson, not sure how that is a huge gamble, the pick will probably be in the late teens -20s. Next year's 2nd brought in another 16M from OS, easily enough to sign a starter or two and a completely different transaction not part of Watson trade. In fact if you look at the value chart they gave up little. They aren't shedding defensive players, they aren't overpaying for a fourth corner or signing a 32 year old safety to a 6M or a oft injured OLB to a big deal. Because they let the players walk, they'll be getting multiple compensatory picks in 2018 including a 3rd for Bouye.
All in all the Texans are poised to sign Hopkins and Clowney and still be able to make a big run at multiple FA next year and have enough comp picks to help fill in the gap between losing the 1 and 2. They are in very good shape going forward cap and personnel wise.