Wow, you have your hands full! I feel ridiculous for ever having been frustrated with getting my one little singleton to sleep. That said, here's what works for me.
Toward the end of bathtime, I start in on this big routine about how tired *I* am. As in "Wow, I am soooo exhausted. I might fall down and sleep right here on the bathmat. I don't even care what PJs I wear; I just want to snuggle up and sleep. I sure hope I have the energy to read you a bedtime story, because I might fall asleep in the middle of the first page. Maybe if you get your PJs on riiiiight now, maaaaayyyybe I can read a little bit. Ohhhhh, yawn." Etc. My son finds this hilarious, even though I do it every single night, but he's also young enough to be suggestible, and he'll promptly decide he's tired too.
In terms of PJ options and bedtime stories, you might also try making their options more, well, boring. With my guy, I basically get him into PJ bottoms and a shirt for the next day, to minimize the ridiculous, rushed drama of getting to school on time. But it also eliminates huge, endless discussions of which PJs are acceptable. We also read the same bedtime story every single night -- Dr. Seuss's Sleep Book. And that's it. No other options. I actually have visions of my son bringing me to college with him, so I can read about Van Vleck & the County of Keck on a nightly basis. But mine is older, and reads on his own a lot, so this doesn't really cut into valuable reading time.
Anyway, you've got 3, all under 5. The fact that you ever get them to sleep, ever, proves you're an amazing, incredible mom.