I would also not have canceled Numb3rs. The existing premise was getting old, but with the last episode they were practically begging for a reboot. Most of the original cast was moving away, with the Charlie and Amita moving overseas and most of the FBI group leaving for various places. The show could have continued with Larry and his friend taking over as the analysts, eliminate the math-solving-crime angle and switch it to physics and engineering-solving-crime angle. This would allow for a whole different set of approaches and whole different set of cases. This would give the Dad, who is staying around, a chance to be more involved. Then they bring in a new head for the FBI group to replace Don and several additional new members, leaving those familiar with how effective Charlie and his colleagues had been in a small minority.
Instead of having Don pushing for Charlie from the top, you have the remaining lower-level guys having to push for Larry to be accepted by the incredulous new guys and their especially incredulous new boss. Plus Charlie, despite being a genius, rarely acted that strange and could explain stuff to laymen well, but with Larry's eccentric behavior and difficult explaining stuff it would be much more difficult for the old guys to convince the new guys to let him get involved, and the old guys would have to do a lot of translation. This would force Larry to develop better communication skills over time since he no longer has Charlie and Amita to translate for him and even the Don had difficult understanding him. Charlie and Amita could still appear as occasional guests giving advice remotely, but their involvement would need to be kept to a minimum and phased out over time.