I'm not sure if you mean 3/4 of a cm or 3 or 4 cm. They look bigger than 7.5 mm to me. Anyway, the one on the left might be a Plectranthus and the one on the right might be a Sedum but I'm not sure. Identifying plants can be tricky when they are small. A Sedum would probably want a better draining mix than you have. I'm not sure what soil mix you used already but it looks like it might be mostly peat. Usually we recommend cactus and succulent soil mixed with perlite at about a 1 to 1 ratio. Sometimes more perlite is used. The objective is to get a soil mix that won't stay wet for too long but how long it stays wet can depend a lot on where you live and if the plants are inside or outside. The Plectranthus, if it is the one I think it is, is a common house plant and tolerant of different soils and watering habits in my experience. Might be best to not keep both plants in the same pot. I'm not sure if your plants need more light or not. The Plectranthus is a scrambling plant. The Sedum looks like it might grow more compact if given more light. I don't recommend keeping them on a table in a room.

...and there should be a drainage hole in the container (if there isn't any). Container is too large, smaller would be better. Not sure, but it looks like plants are potted in black pot - that wouldn't be a problem, except if it sits in the excess water that is in the bottom of outer pot.

Give them sunlight, and they won't be fragile anymore

looks like a plastic pot slide into a pretty pot.. perfect !!!! ... just make sure you dump out any water that accumulates ...

all succulents.. like a drink of water. .and 99% flowing out the bottom.. and that is why a hole in the pot is very important ...

and for 99% of it to run out.. the right media mix is important.. yours is mostly peat ... which holds a lot of water ...

so the trick for you.. other than repotting .... would be to weigh the pot.. or heft it in your hand .... and let it dry until its much lighter.. and then water it ... and not water it again until its almost dry again.. until the pot is light again .....if you had a kitchen scale.. you could go all scientific on that ... weighing the water in it right now ....

they sure look happy now .... so they must have near perfect water ... dont try to love them to death.. by watering them to kingdom come ...

ken

The sedum on the right could be S. rubrotinctum.