I have been running mud trucks and trails rigs since the early 80's and I have found that lighter vehicles can do better in the mud and on the trails than some heavy vehicles. A jeep with lockers and the right tires is light enough to go a lot of places you may never get with your 250. Also if you get a big heavy truck stuck it is quite often a pain to get them out but I can easily (in most cases) pop a jeep out of a hole with little effort with my 2500 diesel. Also the suspension works a lot better on a 1/2 ton than a 1 ton for most all off road events. Your 250 suspension will tend to bounce which can cause you to loose traction and forward momentum on hill climbs. If your blasting up a muddy hill a longer wheel base (with a light suspension) seems to get the job done better with a lot more lateral stability but if your picking your way thru rocks the shorter wheelbase tends to win. Not always, depending on setup, but on average the above plays true.
So without being on the hill you were on I can not answer your question, your 250 might run right up that hill just fine. Did you try the jeep with the lockers off?
I have seen open differential Toyotas and Nissans running with the full size trucks with lockers and doing just fine. Now if your running AG tires and 2.5ton axles with 500+hp then were talking a completely different game