Does this mean i should avoid small sticks and brush thats attempting to regrow???? Dang, I hope i didnt buy the wrong equipment for the job.
It depends on the job you need to do!
The mower you have appears to be a mower with three blades that probably overlap and appear much like any lawn mower blade (hole in the center and cutting edge at both ends, blades about 1/4 to 3/8 thick). These will cut grass and weeds well and can clear some smaller saplings (less than 1.0 inch diameter?). The grass will be fairly well shredded by the time it leaves the mower deck. If the grass is very tall (12+ inches) it will clog the mower and the outlet - probably. You will probably be limited to 5 or 6 inches cut height. As your mower has, most are belt driven to some degree.
A rotary cutter is less of a lawn mower and more of a shredder (they are also known by the name shredder and slasher as well as brush hog) that will cut grass and saplings up to a few inches in diameter (depending on the size and the duty of the equipment). The blades on these attach to a rotating arm or disk under the deck. The blades have one hole at the end and one cutting edge, blades are about 1/2 to 3/4 thick and pivot around the bolt if they hit the "immovable object". There is usually one central rotating disk with two blades 180 degrees apart. The larger decks will have two or three sets of blades on two or three rotating disks that are located across the deck. They generally do not shred the grass too much and leave a fairly rough looking cut and some visible debris behind. They will cut fine blade grass and also cut fairly thick grass. One common use is to cut the fields after harvesting corn and similar crops where stalks remain after harvest.
If you have mostly fields with grass you will be fine. You may need to cut the larger saplings down by hand and make sure the stumps are below the blades of the mower.
If you are trying to clear paths through saplings and undergrowth then you may struggle.