most all of the systems i work on large and small have either variable speed condensor fans or have fan cyclers on them... in fact a lot of manufacturers "low ambient kit" is nothing more than a fan cycling switch.. then again ive only ever worked on domestic space conditioning and not coolers or refrigerators...

in my case there;s always been enough heat transfer at the evaporator to keep the head pressure up at the condensor with simply cycling the fans...
-Christopher