The low needle is typically at a lower setting than the high. Whether it's correct or not depends a lot on how much each is open. The low needle can impact fuel delivery all the way up to 4,000 rpm or so in some cases, while the high needle position can influence the low side performance if it's open too much. Factory suggested settings are those recommended to simply get the engine started. They are not flight tune numbers. All engines use a factory setting as a needle location that will let the owner start the engine in preparation for further tuning. Typically that setting ranges from 1-1/4 to 2 turns open for both needles, with 1-1/2 turns open on both needles as a very successful starting point for most carbs.