Which player would you have drafted? and which one of our starters are you replacing with said player?
Really, there were 4 positions we needed, not just the 3 you mentioned -- CB was need #1, way more than WR, ILB & ST. So, we used pick #29 & a few more to get a certified All-Pro CB. Said CB is also fantastic in run support, a much needed add now that Love is in the air... twice this year. So we used a draft pick to get much better than it was before.
The other 3 positions were indeed "needs", but all 3 could be / have been addressed with later picks, because none of them would "start" right away. Even if we used #13 to get Lemon, KC or Cooper, there's a good chance they'd get less than 50% of the WR snaps per game. (you think that'd sit well w/ Lemon? yikes, good luck w/ that guy Iggles.)