We have 4 prenatally exposed kids. Some days it is...well...it is what it is!
Some of our kids were pretty aggressive, particularly when they didn't have the skills to communicate their emotions very clearly. It takes TIME and alot of patterning. By patterning I mean that I told the kids the appropriate emotion and way to behave. Sounds bizarre and controlling, but it is what they needed. They NEEDED to know what was the right thing to do and I needed to tell them what it was.
Additionally I've found that my kids can out-perseverate most other kids. My current 'terrible two' year old is very good at having long lasting fits of anger and aggression. Amazing to me at times - and he's my 4th child, and we've also fostered kids, so it isn't as though I'm not familiar with kids and their stages of development, or having stubborn two year olds! We work to make sure that he is up on his meds for reflux, since pain can be a trigger for aggression, we watch for signs of SI stuff, we do all that we can to make sure there is not an underlying reason for the tantrums, but then we batten the hatches and just ride it out. We do not give in to demands made in nasty voices, either whiney or yelling. He may not throw anything in anger. He must pick up anything he messes up while having a temper tantrum. He sits in time out for 1 minute (we don't do a minute per age as I think he's a little immature).

We make him go pick up, we make him ask nicely, we make him apologize for hurting siblings, we make him give back things he grabs, and this all takes T I M E, and lots of it.
For some kids being in groups of peers is not a good idea. We tended to avoid this. Not really out of fore-thought, but because we homeschool and our kids play with other families of children, so there may be one or two kids in a group of 10 or 15 kids who are the same age, but overall they were playing with a mix of ages. The beauty of this, we found, was that the older kids learned to help the younger kids and the families were willing to help by making some accomodations for my kids with various problems. In general having a mix of ages made for happier play dates and helped everyone stretch their social skills in a variety of ways.
One of the problems that needed attention during play with other kids is that they were/are social dysmaturity, so they act/ed younger than their chronological age. The other kids have had to adjust for this, and they did so with no fuss. Another problem is the lack of ability to regulate their emotions without prompts from helpers (ie: parents, supervising adults and even other kids who could figure this out). They need/needed help to de-escalate their anger or frustration, much as a toddler does.
Additionally, and this was a huge factor that we didn't recognize for 2 years, is the sensory integration component. MANY children who were drug exposed have SI problems. Our oldest Ds happened to have a big case of tactile defensiveness, and could not stand to be touched. BOY, did we have a whole new world open up before us when we finally got that information! What a help to be able to know that he was throwing himself onto the floor screaming because someone TOUCHED him, not because he didn't get his way or whatever is a 'normal' trigger for tantrumming! Then we got to explain this to others, which helped at play dates, believe me! LOL
I guess the key is to know your child, work to figure out what frustrates them, and then work to figure out how to give them the tools to overcome this frustration. SOMETIMES kids need to have parents remove the frustration, or run interference for them. Not always...and that's another fine line to work to figure out. Do I accomodate this area, or do I look for tools to train the child to figure this out on their own? And that is an ever changing thing; the kids figure out stuff more on their own, you have to figure out when to remove a crutch and when to give a different one...it gets intense at times to keep ahead of the game. LOL
Share whatever you find that works, too.
