I find it interesting that you call CBS out on that since that network, IMO, is one of the most stable as far as putting a show on and sticking with its schedule. What you describe is FOX which is by far the most unfriendly network when it comes to nurturing shows.
The Unit actually got 4 seasons which surprised me. I liked it a lot as well and will be sorry to see it go, but it's not like CBS put it on one season, moved it all over the schedule and then ended it.
Crossing Jordan wasn't a CBS show, it was NBC, and I only remember seeing that switch nights one time but it may have moved more. Plus it ran for 6 seasons which is a lot, really.
And unless something has changed in the last week, Life got cancelled.