Well, yes they are different. But they are used for the same purpose.
They are both a repartitioning hormone (one meant for hardening and fat loss, with very lean, but somewhat meager weight gain). Stanalone (MMV2/3) has more androgenic effects (strength, aggression) than Furazabol (oristan-a... aka furazadrol), but I leaned out more on Furazabol. So, pick your poison... I would say that the MMV2/3 would be better if you were more concerned with weight gain, and the furazabol would better be suited for fat loss. Since you are already going to run the Hdrol, you are going to gain size and weight from that anyway, so if you want more aggression hit the stanalone, if you want more re-partitioning hit the furazabol.
The beta isomer is stronger, but MMV3 with it's alpha isomer is sub-lingual, which means that more should be absorbed into the bloodstream, so the effects I would think would even out. I have yet to try MMV3.
The reason that I say not to take both is that like I said above, more doesn't always equal better. You only have so many androgen receptors and the Hdrol is going to take up most of those, as it is a type 1 anabolic, which binds to the androgen receptor. Furazabol is a type 2 anabolic, which doesn't bind to the androgen receptor, which makes them a PERFECT combination as far as how much of the hormone you can actually use to build muscle. If you take two type one anabolics, you run the risk of wasting some of your dose, as you may totally take up all the androgen receptors and not be able to absorb any more of the hormone, rendering it kinda pointless, and just harsh on your body. I mean, you COULD take M1T and Superdrol at the same time too... but I wouldn't recommend it, you'd probably hurt yourself. While taking both furaz and stanalone probably wouldn't hurt you... you'd have better results using one or the other on another cycle, rather than just running 3 hormones. I've done my experimenting, and 2 hormones a cycle is all I run these days. I am honestly not sure if MMV2/3 is a type one or type two anabolic though, I'll have to look that up.