Regarding rotary cutters you must have looked at Brown's 400 series which is only their entry level cutter not designed to compete with the Woods 1000 series or Extreme line. The cutter that actually targets the same market is their 600 series which is their extreme duty product. Comparing apples to apples the Brown makes the Woods look like a toy. Compare the specs Brown 600 series vs Woods Extreme: 5/8" thick x 6" wide blades vs 1/2" thick x 4" blades, 16,000FPM blade tip speed vs under 14K, 1/4" deck thickness vs. 7 gauge, CAT 8 driveline vs CAT 5. Even the gear box is a beast. I know it says only 145hp rated but thats constant power not a peak rating. Keep in mind that Brown rates all their products very conservatively where other manufactures slightly over promise. For example Brown says their 600 series is rated up to 4" material and so does the Woods 1000 series or Extreme line. However, Brown considers hitting multiple 4" trees ok where Woods is considering only 1 or 2 at a time. The 600 series Brown will handle 1 to 2 (5") hardwood trees with no issue. Question is, is the tractor stout enough to take the abuse LOL! Both are great products just showing the differences of the two ratings. If you ever have a chance to see both in person you will instantly see what I'm saying. The only problem is that I don't think Brown makes a 5 footer in the 600 series. Again you might need to call and check. If not then Woods is probably your best bet which takes us back to the top where you started.
By the way, the Brown medium duty 400 series comes with the same CAT 5 driveline, 7 gauge deck, and 1/2" thick x 4" wide blades which are all the same as the heaviest Woods cutter made the 1000 series Extreme.