Most NFL coaches agree: Kirk Cousins is a system quarterback. A high-level system QB, sure, but a system QB nonetheless. In other words, Cousins is not someone you build around—he’s someone you plug in. His arm is good, not great. Same goes for his athleticism. His pocket mobility and toughness have improved each year, which is notable given that most NFL systems center around traditional dropback passing. When playing on-script, Cousins is efficient. But off script, he can be erratic.
Coaches, especially those on ready-to-win-now teams, don’t love drafting and developing a system QB. It takes more work than potential star QBs, but it often comes at the same level of risk (a first-round pick) and with the same worst-case scenario (a bust).