First of all, there is really no replacement for drainage holes. That could be one of the reasons why your plants aren't looking so great.

However, I think most of it lies in the soil. These succulents are overwatered. This can happen from using the wrong soil, even when you aren't watering much. A super easy soil mix that works, is 50% perlite (sifted through a kitchen sieve) and 50% any commercial cactus and succulent soil. While I personally don't use this mix, there are a lot of people on this forum that do.

In addition, I think these are also suffering from lack of light. The majority of succulents like A LOT of light. As much as you can give them. Just be careful not to burn them by putting them in high light levels directly from an area that gets little or no sun.

The above is basic succulent care, so if you want to save your plants you need to improve the soil, light, and particularly the pots. You'll need small pots (not bigger than the ones they are in) with holes in the bottom. After transplanting into the new soil and light, don't water for a few days.

Hi Arny, i totally agree with the comments above. I'd just add a warning with the perlite, When you sift it, consider rinsing it outside. I do through a kitchen sieve. The amount of dust was awful the first time I did it, dry AND inside. I had to leave and come back later lol