Okay sounds to me like maybe your not sure what combos will work on your tank! I don’t think you are iver stocked but maybe the fish are a bit incomparable... I get it we’ve all been there! You get a tank and you get super excited about all the possibilities and the store employees don’t actually know enough about the fish’ needs and compatibility or they just straight up don’t ask any questions bag your fish and send you off etc!! In my opinion, I would say you don’t need to worry about the number of shrimp. If you have like 10 shrimp and a 5 gallon tank I count it as two full-size fish towards stocking/bio load. Now what would be compatible with your cherry shrimp? The answer is not guppies LOL! Guppies are a hard water fish and although some people can manage to keep cherry shrimp in hard water I just don’t recommend it as it was really hard for me to keep measuring and adjusting the hardness when I tried it and it didn’t do well so I switched over to softer water and my red cherry shrimp are doing great. I have a bout 30 in a 5 gallon tank because they just breed like crazy! Something to keep in mind, they will only breed to the extent of a population that will survive in the tank, any remaining or extra shrimp will just die off and feed the ecosystem and you’ll have less shrimp and you won’t even notice because the other shrimp will just devour them and use the nutrients from that shrimp to survive. I would say getting a bunch of cherry shrimp and a bunch of little neon tetra (6) swimming around there will give you lots of movement and great colour against all the plants that you had in there and bonus: with a relatively low bio load!!!!! If you absolutely can’t get rid of the guppies then I would still get a couple more shrimp add maybe 4 more RCS pick the smaller slimmer looking ones to get a male but make sure they’re still lively (photo below of red cherry shrimp comparison) ask the employee to catch a bunch of them and look at them in the container and pick out the ones you think are females and put them back so you keep the males! Try to keep up with your water changes every week do about a 33-40% change with de-chlorinated water. If you go to a pet store some times they have little turkey basters that help remove fish poop for smaller tanks such as these (good idea to keep your tank looking as clean and nice as it is!!) and if needed for extra filtration you can always set up a very small sponge filter which will help with biological filtration and give your shimplettes a place to hide and eat and also give your tank a bit of extra surface irritation to help with oxygen levels
hope this helps if you have any questions feel free to message me or reply I’ll try to answer quick for ya!!