Well, first of all, i dont do inches and stuff (That's right, im a meter user!). So lets say a cat is around 20-30 cm high (ground to upper back). But then again swat kats characters is walking upstraight, which would make them like 45-70 cm high (as they walk). A normal heighted human (in sweden since i do not know middle heights in other countrys) is around 177-181 roughly rounded to 179 cm. This is 5' 10.5" (according to a converter which i have no idea if it did the correct convert). That would indeed make the cats very big. If we try to look at this scientificly it could be very possible (since they dont have to be pet-cats but they can be a wild "predatorish" cat, lets say a tiger or so). But if we look at it through the eyes of someone that watches the series, one could suppose the cats in megakat city grows differently from our cats at "earth?".
I looked up the average height around the world on wikipedia, which stated that the highest average height was in Greece, where the mens average height were 6' 6", so if t-bone is "only" 6' 11'' that would certainly make them higher than humans.
Then again, we can only measure them from the proportion acording to objects we see in the series, for example how tall they are in proportion to a car, helicopter, door, building etc etc. But if they were as tall as your source states, they would be, and that if they were they would be taller than humans, then how **** tall is feral and dark kat

?
Sorry if i only confused you even more with my half-good english, but this is my thoughts around it
