I dont have three, but i have two 3 yr olds who are 2.5 weeks apart. My foster (soon to be adopted) son was placed at 16.5 months old. Luckily he and my adopted son got along much better than the little girl i had just before him (who was 11.5 months when placed, my adopted son was about 3 or 4 months older, and it was a terrible match), and its mostly been fine. Neither of them have special needs or attachment issues, however they are VERY very different personality wise. Sometimes thats great, because they can bring out the best in each other (the older is more cautious than the younger who is more fearless) but other times they clash and i feel like i break up fights all.day.long, which is partly the age and partly because one is super sensitive, a bit OCD, rule oriented, quick to react physically when upset, the other is more laid back, but quick to dissolve into a melodramatic meltdown and the slightest disagreement. Mostly they are best friends.
Given the delicate balance between them, i am VERY hesitant (to the point where i likely dont even consider it) to add another child even close to their age, if i adopt again it will either be a baby under 1 or 2 years old or a child around 5-7. (Though i recently added my fs' bio sister who just turned 9 and thats been extremely challenging and im a bit scared to adopt another older child!)
We also had to wait for the appeals process to play out, and that took over 9 months to resolve, and even after that the dad STILL appealed to the state supreme court, im not sure if thats over yet. (Everyone was confident they wont hear his case.) We've just passed the one yr mark after TPR and still awaiting finalization, its very frustrating. I was so sure we'd finalize before the end of last year.
One challenge im currently facing is that people ask me all the time (no lie...in one restaurant visit four people asked!) "are they twins??" and its very awkward for me. They dont really look alike, and i feel like a liar to say "yes!", but if i say "no" and they ask how old they are, and i say "2.5 weeks apart", that invites questions like "oh are they cousins? are they both yours? so close, how did you manage that?!" that sort of thing, which then brings up adoption and at their age im trying to practice not telling every random stranger their adoption story yknow? It just feels weird to call them twins when they are not.
Overall though, i love bunches of boys...your group sounds like lots of fun even if exhausting!!!