TWINS or 2 KIDS @different age, which is harder

My hubby asked me about, which is harder having twins or 2 kids of a yr apart. My hubby had twin boys on his 1st married, they are turning 12 this coming June. He told me that it seems twins is easier to take care of than our 2o months old son and 7 months old daughter. He said having twins, they tried to do things at the same time. Like they fed them at the same time and they nap and sleep at the same time. With our first son we used spread a blanket on the carpet and let him stay there a lot, for tummy time till he started crawling and walking but when we had our daughter, we cant just leave her on the carpet, or on the couch cause of our older son. Cause whenever he saw his sister he want to sit or hold her, he is sweet and gentle towards his sister but we worry about him hurting his sister. So we tried to be more careful when he's around. Most of the time during the day, when my older son is napping my daughter is awake, so I dont really have that much time for myself when my hubby is not off from work. So maybe having twins is easier compare to 2 different age at a certain age. My son was spoiled a little during his infant years. He slept with us on our bed till 11 months which he still does from time to time. While our younger daughter slept all through the night on her crib sometimes I ended up taking our son out from his crib and put him beside me when he wakes up at night crying cause I dont want him to wake her sister up too. My kids are handful but I love being SAHM cause I'm having this opportunity to watch them closely @this early age.