Expanded defensive ability in several areas could result from Bears signings of Tremaine Edmunds, T.J. Edwards and others. Free agency from the outset blessed the Bears defense with ability unavailable to last year’s team. Then the benefits immediately slowed with fewer signings on that side of the football. Still, what they’ve done so far in the offseason leaves the Bears in a better position to address underlying problems. Their defense actually ranked lower last year than their offense, as they finished with most points allowed for the first time in franchise history. So any improvement is welcome and there was…