You can use those kind of setups, they will work.

However, there are a few drawbacks. My first concern is that it is setting up for extra "points of failure" compared to a normal battery pack. All the springs and joints in the plastic holder, plus the contacts between the cells and the holder, it's a lot of extra stuff go to wrong.

Second, any time you have a mecanical-only connection like that, you have some voltage loss. honestly don't know how much voltage you might loose with all those extra connections. I suspect it's not a lot, but then again, those holders are usually meant for the normal disposeable batteries that have 1.5 volts/cell instead of 1.2 for the NiMH cells.

So, before you actually fly it, check the pack with a meter and see how it reads. It should be fine, but better safe than sorry. I'd also check it fairly frequently to make sure everything fits together well, any looseness around the cells would be a bad thing, obviously.

If it was me, and I had the cells, I'd look at getting the materials and equipment or finding someone near by to just put the cells together in to a soldered pack.