The workflow I know of, which is very popular right now, is the Z-brush->Cinema4D->Substance->Unity pipeline.
This workflow is what I think the guy you were talking to might have wanted you to learn, though I could be wrong.
This workflow is where you first make what you want in Z-Brush, you sculpt it, and you do not care about typology at all. Then, you export that out of Zbrush and bring it into Cinema 4D, this is where you first retopologize it, and then you rig it.
Next, you bring it into substance painter for texturing, finally, you bring your now finished asset into your game engine of choice, in this case, unity.
The reason this workflow is popular is that especially for games, having characters with a low polygon count as possible is important.
Making a character from scratch with good typology is very hard, and people found out that it is faster just to sculpt what you want, and then retopologize it, or rebuild the polygons on it, making it much more optimised for games.
Now, this workflow is almost never done by one guy in a professional situation, you have your guy who does sculpting, then you have another guy who does the etiology, and so on.
Also, this is a very expensive workflow, that only the more professional studios use because there is a lot of paid expensive software involved in this.
This all said you could do all of this same workflow, with just Cinema 4D, you sculpt in Cinema 4D, then you retopologize Cinema 4D, then your texture in cinema 4D, and finally you send that out to your game engine.
Its just harder doing this with just cinema 4D, because its sculpting tools are not as easy to work with as Zbrush in the sense that Zbrush gives you a growing mesh to sculpt with, so you can start with a sphere, but end up with perfect quads for your polygons on your finished dragon head.
All this means you don't have to buy all of this. I would recommend just starting with Cinema 4D, and learn the process there, once you have this technique down, you can then learn new buttons to apply that same technique in that software.
