3 year old behaviour

[NCforthis111]

DS is almost 3.5. his behaviour recently can be a little challenging at times, but only at home. I'm wondering whether he is actually misbehaving or being a three year old.
DH is of the opinion that he is intentionally being naughty, shouts at him, and just expects that DS should do as he's told, because 'we said so'.
It strikes me as being authoritarian. I'm not into the 'never telling them off' approach amd I don't want them to grow up with poor behaviour, but I can't help think that DH is being unreasonable in his expectations of a three year old
I do the majority of the 'hands on' parenting, but DH feels that it's not enough discipline.
DS is well behaved at his nursery 3 days per week and with his GPs the other day each week (I work 4 days, DH 5 days).
He's well behaved out in public. He's more often than not, also well behaved when at home with me.
Some examples:
Taking toys from his sister, if she's got one of 'his' toys.
Hitting (it's not hard, but the point is, he knows he shouldn't do it).
Pushing his sister (1 year old) or blocking her way so she can't get past and cries.

He knows he shouldn't do these things and will look you in the eye who he does it - he's clearly waiting for the reaction.
My response is a firm no! No hitting! while down at his level, explain that it's not kind and he's made his sister sad, for example. Then distract - how about coming to play with the cars with me.
DH is now invoking the naughty step because he thinks he's just poorly behaved, when DS will get up and laugh when you turn your back.
He's told DS to stop being feral this morning and to do as he's asked the first time. DS doesn't understand feral of course, but I don't want him to be internalising these things as he's older.
His behaviour does deteriorate when he's tired or hungry. I've been in the home office this morning and have heard DH shouting at him a fair bit. He's definitely tired after an early start (he had an early night as he was under the weather a little yesterday). I came down to help DH get everyone out of the door to drop off at GPs for the day and DS was definitely in need of a snack, as he took the pepper sticks out of his lunchbox while I was taking them from the fridge and putting them by the front door.
Am I being too defensively and passing off genuinely poor behaviour as being a toddler?
Is DH being unrealistic with a 3.5 year old?

I'd appreciate your honest responses, even if it's that I'm being too laid back - I don't want to be storing up bad behaviour in the future...

Your husband sounds unreasonable and your son sounds like a regular three-year-old to me. My kid is almost three but she’s definitely testing her boundaries - hungry/tired/under the weather - all triggers like you said. Children can be incredibly frustrating. I think your approach sounds great / firm enough, he’s just testing you. It is hard not to lose temper and shout so I sympathise with your DH but in the long run it’s bad for parent and child and doesn’t get results. Children will do as you do not as you say, you have to model the behaviour. If you shout they shout. I don’t think ‘because I said so’ is good enough , depending on what it’s about.

Hmmm I was with you until you described the behaviour and your dh reaction. I would be ok with the naughty step for pushing or intentionally upsetting much younger sibling. I dont think stop acting feral is helpful but it won't cause me great concern if I herd my dh say it to one of my children. And he should listen first time. Maybe not always but you shouldn't have to ask repeatedly for whats expected. I agree with u though that they shouldn't have to be perfect all the time and I do let behaviour thats comes from tiredness hunger frustration slide a bit more. Mine would be on the naughty step for repeatedly ignoring me. Hurting a siblings intentionally. Not invited to play cars with me. Think you need to meet in the middle.