its would still be hard , becuz of only 4 after a few generations inbreeding would ocurr , even if they did die off or are endangerd take in example florida moutains lions have many health problems due to the fact that population is very very low and inbreeding is taking place. so the only way to save a speacies would to find a another very simliar related speacies and able to cross breed it with the cloned DNA and be able for them to produce off spring. some animals arent fertile when u cross breed them