No, not dumb at all. ERJ's may not require more crews than a 700/900, but since the staffing for 200 is mixed in with 700/900, ERJ staffing will be higher than the overall CRJ fleet.

200's are much more likely to arrive at a small outstation and stay for ten+ hours so the same crew can do the am departure. Bigger RJ's at larger outstations or hubs are likely to get in late and leave early, thus requiring two crews on the overnight.

Also a 200 doing west coast 6-leg days with a lot of ground time can go all day with one or two crews. A bigger RJ doing longer legs will burn through the crew's block-hour limit in a shorter time period (less wasted time on the ground) and will often need three crews in a day.