2 month old baby - light sleeper

Hi, anyone facing problem as me? My lo seems so hard to sleep in the afternoon. When he latch, he will fall asleep. I will wait for a while before putting him in his bed. But then, he will wake up easily. I have 2 other children aged 6 and 4, they like to play loudly and will wait lo up too. I know he is sleepy, but it is hard to make him fall asleep. Is it normal for baby to not sleep alot at this age? Im just worried he didnt enough sleep and causing problem with his development, maybe? I dont know, people told me baby and children needs more sleep as it is good for their brain. Tia.