With Lamb or Cooper, i don't think it has anything to do with two paid WRs.
We took Lamb because he was valued as the best available prospect on their draft board, regardless of offense or defense.
In fact before we drafted Lamb, we only just re-signed Amari Cooper to a record contract at the time, only a month before we drafted Lamb in 2020, i believe.
it will probably never be publicly reported (unless Jerry accidentally spills the beans) as factual as why we trade Cooper away for a bag of peanuts.
Maybe the club did not think Cooper's on field production, his tendency to disappear in key games, (especially vs top coverage CBs) .. for a guy that was supposedly the featured lead WR, or rumors of his stand offish personality.
Club seemed like they could not wait to get rid of Cooper.
Seemed " personal " more than business decision, imo.