In my experience, large estimates are only ever Rough Orders Of Magnitude. Our teams do not pull any work in to be done unless they've broken it down to the sma

In my experience, large estimates are only ever Rough Orders Of Magnitude. Our teams do not pull any work in to be done unless they've broken it down to the smallest estimated components. Anything with a large estimate is inherently inaccurate and not ready to plan around. The situation you described seems quite broken