Last May, we did all 3 of those restaurants without a reservation but I can see Boma dinner filling up. There is also a shuttle that can transport you back an forth between Jambo and Kidani, though we felt the 10min walk was minor.
I agree with the above post IF you don't have possibly difficult toddlers with you.
The 10min walk wouldn't have been that big of a deal IF we
1) didn't have an ADDITIONAL 10-15 min walk to our room at the end of the hall and
2) have a 3yr old who was 40lbs (99.98 percentile) at the time, hated the stroller with a passion, didn't walk very fast, and slept very poorly (did I mention he hated the stroller)? A 10min walk with a toddler can seem like eons, or take eons.
Note the OP has TWO toddlers.
So really, our walk was 20-25min. The shuttle took as long. It took 20-25 min just to go to the cafeteria, or to catch a bus to any of the parks. My toddler refused to nap unless in a dark room so returning from the parks mid day for a nap plus our super long walk to kidani wasn't very fun. It was an excruciating stay for us.
We couldn't get into boma Sanaa or jiko at 5-6pm. Anything later meant a screaming hungry toddler.... And then a screaming tired toddler after dinner. We went to the cafeteria instead.
Like I said, it's not a bad resort. If just wasn't for us, particularly given our difficult inflexible toddler. We also learned to plan ad nauseum after this trip.
If the OP has easy toddlers, then she's lucky lol. She may find a 10-25min walk with them just to get anywhere not a big deal. She may also have kids that don't have to eat at 5/5:30pm, naps only in a bed in a dark room, has to go to sleep at a certain time, etc.
Hopefully the OP has easy toddlers... But staying close to the lobby and making ADRs or having food in room can't hurt!