Chinese alage eaters often times become aggressive as they mature and are generally poor at eating alage. Have observed the chinese alage eaters attempt to rasp or (suck) the slimecoat from large slow moving fish such as Discus,Angelfish,Severums etc. With smaller fish ,they simply chase them until the fish become stressed and I would not recommend them unless the tank was large enough for other fish to stay clear.
For corys,I agree.more is better, I keep no less than eight with a dozen being more enjoyable both for the fish,and for me.
For a ten gal? tank I would recommend a group of five or six Kuhlii loaches so long as the pH was not much above 7.6 They stay small,do excellent job of sifting through the substrate for food,and don't create much in the way of bioload on ten gallon tank which would prolly be more like six gallons if one considers the amount of water displaced by gravel,sand,and or decorations.
In my view,one paradise fish and a shoal of Kuhlii loaches,, the tank would be jsut about perfect stocking wise assuming weekly 25 to 30 percent water changes take place regularly.