Nope, that's backwards. If the ram is your stop, then the ram will move it's full stroke regardless. All other things remaining the same, that means your steering box must turn the sector further than is did with the longer pitman. Depending on how much throw your box will tolerate, and how much shorter the pitman may be, this could be a major problem and ruin your box or break your frame or???
Better would be a longer pitman (if it did not interfere) since it would take strain off the box and turn faster. The lost mechanical advantage due to a longer pitman would then be made up by the hydro-assist.
It's simple geometry. Think about it in the extreme if the pitman were turned 90* to the frame rail. A shorter pitman will have moved your steering drag link less distance for the same gear box 90* rotation. The effect is most pronounced at 90* where the difference in drag link movement is equal to the difference in pitman arm length, but the effect is increasing from "0" as soon as the pitman moves off parallel with the frame.
Will this be a problem for you? Depends on how much shorter the pitman is, how long your knuckle arm is, and how far your ram allows the tie rod to move before it “limits” the steering. And don’t forget to consider “edge cases” where static extremes are exceeded due to things like articulation, bump steer, frame/link flex, and so on. It may be fine tested setting level, or even articulated with a front end loader or something, but then on the trail, when things are really getting loaded, you’ll break a sector shaft or blow the end of the box. Not much fun...
Not to be rude, but you (and that means anybody, not picking on you specifically) really shouldn't play around too much with steering components unless you spend some time doing the math and fire testing the results in controlled/safe conditions. For anyone who is not comfortable with going the whole way to do it right, then I would strongly suggest using a known good off the shelf system from one of several good vendors. It would really suck to crack or damage something on the trail, but not fail completely until your rolling 60 down the freeway and hit a bump or something, then you have NO steering at all as you careen around at random, possibly into oncoming traffic. This is probably the most important and most sensitive system on the vehicle with the possible exception of brakes, though I would rather loose brakes than steering at speed...