Merope 5c has a radius of 1478km. If my math skills have not deserted me, this means a diameter of 2956 km, so a pole-to-pole route would be 2956 * Pi/2 km or about 4643 km long. The top speed of an SRV is about 35 m/s, so this would take about 1.5 days of round-the-clock driving time if we can keep top speed all the time. If we hit rough terrain (and Merope 5C has a lot of that), the speed will be lower. My gut guess is that the average speed is maybe a third of the top speed, so we are talking about 4.5 days. However, there is one show-stopper: At the equator, you would have a distance of 2956 km * PI / 36 = 258 km between SRVs, so we would miss stuff.
My estimate is that the scanner has a range of maybe 1 km. To ensure that we really cover everything, we need to place the SRVs 1 km apart at the equator, and then all drive to the pole, return to the equator, and repeat the procedure for the second half. We only need about 9300 commanders for this.
Piece of cake.