Well like I said, don't leave it sitting out for too long, just put it back in the fridge if he doesn't eat it in 15 - 20 minutes. No healthy dog will starve itself, he'll eat when he's ready. And you aren't starving him if you're offering him food for every meal. You just don't want that food to be dried out, crusty chicken that sat out for too long (not saying you're letting it sit out that long, just saying it's important to keep the same meal fresh and appealing rather than letting it get nasty). Some dogs will go up to 5 days without eating, and that's ok.
I think that adding all this stuff to it is just encouraging his pickiness right now because you're catering to his wishes of getting something else to eat. When I was a kid, if I didn't want to eat what my mom made me, I would just go hungry for that meal because my mom wasn't going to make me a whole new meal just cuz I wasn't wanting what she made that night. And if a kid won't eat their veggies so their mom smothers them in butter to make them more appealing, then the kid licks off all the butter and leaves the rest, that's not really healthy either (not that raw eggs aren't healthy for dogs but you get the picture right?).
Anyway, if he goes 5 days without eating and still won't eat it, you could always try searing it in a pan for about 2 - 3 seconds on each side to bring out the natural aromas of the meat and make it slightly more appealing to get him started.
I'm glad your girls are doing well on it, they sound like a fun pack of dogs!
