The playing outside after dinner until 7:00 is too late.... because, kids need to "wind-down" before bed. Winding down can take 1 hour to 1/2 hour.
After dinner... I would NOT do anything that gets them keyed up and hyper. ie: playing outside after dinner. This will only prolong the ENTIRE going to bed routine... and exacerbating the whole wind-down process, impeding it.
Then, you end up RUSHING everything just to get them down by their bed time. Which inevitably will be too late... because everything (ie: the winding-down portion of the routine), is started too late.
Can't chores & playing outside be done BEFORE dinner? Not after.
I would, have them then do the story time and bed/brush teeth routines... BEFORE 7:30. 7:30 is too late. Plus, just brushing their hair takes 1/2 hour for you... and them. That is too long. This then prolongs EVERYTHING... just because of brushing their hair. Next, except for the 2 year old... can't they brush their own hair? And if knots/tangles are a problem and therefore prolonging how long it takes to brush their hair, use a leave-in detangler or conditioner. That is what I do with my Daughter. I use the TIGI brand- "after party" - which really gets out tangles and make brushing hair MUCH easier and faster. Or anything by Garnier Fructis. They have good hair products and hair cremes for de-tangling.
OR... just cut their hair so brushing it is not such a torture and then when they are old enough to care for their own hair... they can have longer hair if they want.
That is what my friend does with her girl. And for my daughter, because her hair is so fine and tangles easily... i do NOT let her grow her hair past her shoulders.
You NEED to get the evening routines done earlier.
AND... keep in mind, that any active play/horsing around/keyed up physical activity... will only PREVENT a child from being able to wind-down and to calm down... and to fall asleep, calmly. If a kid is hyper/keyed up before bed... they will not be able to just fall asleep.
My Husband, used to have a habit of playing with/horsing around with the kids before bed. (after I had wound them down)... then they would get all hyper again and NOT be able to go to bed, much less on time... and it just screwed everything up and their cuing and routine for bed. THEN my Hubby would say "how come the kids go to bed so late and are so hyper?! They need to get to bed earlier....!" Um, DUH, Dude! So I explained to him that I HAD the kids on schedule for bed and calmed down... but him playing with them right before bed only SABOTAGED it all and then I had to start ALL OVER from scratch, to then wind-them-down. AGAIN.
Activity before bed.... only backfires... and then the kids cannot segue for bedtime, calmly nor restfully.
The whole thing also of how long it takes just to brush their hair is a real problem. If they hate getting their hair brushed... then don't. Put it in a pony tail... and that's it. When my girl does not want to brush her hair after shower and before bed, I tell her put it in a pony tail. The next day, her hair is not tangled.
Next, you need to (and I know its not easy), but you NEED to have the girls fall into place. They NEED to be a part of the routine... you sit them down, tell them you are on your own, you NEED them to ALL BE A PART OF THE TEAM.. you are FAMILY... and they have to help. INSTILL that in them. If they give you a bad time... then they need to get reprimanded.
Make tally marks for each one. Then, you can show your Husband... who did or did not cooperate etc. It is a visual aide.
I really know this is not easy... but you need to bump up the entire routines to an earlier time, and quit the playing outside after dinner. After dinner should be a calm time... to then segue to bedtime....
all the best,
Susan