www.lapolicegear.com/black-hawk-strike-gen4-molle-system-m4-triple-mag-pouch.html

could something like this be mounted on a regular leather belt? Are there better options for this?

ETA I'm not high speed or low drag or anything, just trying to put together some emergency gear to train with.

You can use MOLLE pouches on a belt but it depends on a few things.

The pouch listed will be way too heavy to mount on a standard diameter belt and you will experience a lot of flop. On a belt I will mount a couple singles only.

What is the width of the belt? Basically you will need to see where the belt will fit according to how the PALS will line up. Another thing to consider is how high do you want to mount the pouch. This is important because you will want to reduce flop and also be able to get mags in and out of the pouches efficiently.

What is your budget? How many magazines are you looking to carry? Eagle makes belt mounted pouches that may suit your needs as well. You will be tied down to always using them on a belt, but thems the breaks.

I use a couple Tactical Tailor Shingles on my belt for 2 AR mags. I use either a Eagle/SKD Universal or a SOTech Falcon of rht remaining loadout depending on what I need. I do have a subload for my leg if I need it, but there again I will not load more than 2 mags in it on my leg.

Budget isn't too important (we're talking mag pouches not acogs), and I have a pretty surdy 5.11 reinforced belt to hang stuff off of.  I like the idea of the 6 mag holders from that link so I don't have them stashed around all over. 2x4mag holders would work too.

my idea is to have most all the other gear in a backpack except the essential pistol, blade and a leatherman.

I saw someone running 3 mags on the belt at a class last weekend.  He was using a 1.75" 5.11 type belt but because of the small area of actual attachment and the large overall area of the pouches and the mags inside it seemed like they flopped around a lot when pulling one out.  You fighure on a leg rig or chest rig the top and bottom of the pouch it held tight so the mag comes right out.  On the belt the top and the bottom are floating and it is held in the middle.  It worked but didn't seem preferable.  Just my observation.  I think a leg rig or a real low profile chest rig would be more practical.

What is the width of the belt? 6 mags is just too heavy for a 1 3/4 inch belt. If you want to run 6 mags, you're going to need to get a much heavier type belt. If you're going to stay with that style of pouch you're going to need some form of heavy MOLLE padded belt, like something from ATS, Eagle, etc... You're also probably going to want suspenders such as something like a set from HSGI.

Tell you what, use an ALICE rig and pouches and set them in the same manner you want to carry your gear to get an idea if you like that many. Its an inexpensive way to start while you figure out exactly what you do or don't want.  You'll save yourself time, money, frustration in the long run.