Yes, no, and it depends.
Cashmere is made from the hair of the Kashmir goat and gives a lot of warmth for its weight, is highly compressible which makes it great for travel, and has a high loft making it wonderfully soft and cuddly when worn next to the skin. Its insulating properties change with the amount of humidity in the air so cashmere feels comfortable over a wide range of temperatures, even very warm ones. Cashmere tends to be pricier than wools and the quality can vary quite a bit. Cheap cashmere isn't very durable and can pill quite a bit.
Merino wool comes from a particular breed of sheep whose wool is prized for its superior breathability, temperature regulation, moisture control, and
inherent anti-microbial properties. These qualities make merino wool a favorite for intense, cold-weather or high-performance applications. Many people find merino wool to be just as soft as cashmere but more durable and less costly than good quality cashmere.
Lambswool is taken from sheep at their first shearing. It's soft and springy, holds its shape very well, and wears like iron as long as it doesn't get tossed into hot water or a hot dryer. Lambswool is the most hypoallergenic of all wools. Sweaters made of lambswool feel soft and thick and are very warm, even in damp conditions.
"Average" wool comes in different grades. Virgin wool is the softest. "Super" wools are graded according to the fineness of the fibre; the higher the number, the finer the wool. The softness and durability of an "average" wool sweater depends a lot on the quality of the wool, how it is woven, and any treatments that have been applied to the wool before and after weaving/knitting.
To my mind, it's the quality of the sweater that makes the biggest difference. Cheap wool can be scratchy and awful, but a high-quality "Super 150" wool sweater can be a much better buy than a low-quality cashmere sweater because it will look and feel better for a much longer period of time.
