What do to??

Hello! I need tips from this community on what to do. I have 3 kids (5 yo- 40 lbs 40 in, 3 yo- 30 lbs 36 in, 11 mo - 19 lbs 31 in), and a 2012 Honda Odyssey.

Yesterday my new Britax Frontier SICT arrived. Lets just say WOW... ridiculously wide...

I currently have my 5 and 3 yo in Radians XTSL's, and the baby in an OnBoard air 35. I got the Frontier to move my 5 yo into it so that I can move the baby into the Radian, RF, once he is a year and reaches the 32 in limit (which are both very near)

I installed the Frontier in the 3rd row, in the middle (It seems like the more I stare at this thing, the bigger it gets!) It may be that I have a very skinny Radian I'm used to seeing but wow, it's just wide. Anyways, on the first ride to take the kids to school I contemplated returning the Frontier for a non SICT. Then I thought, what if I move it to the 2nd row for the 3 yo, since the baby will be RF in the Radian in the middle of the 2nd row, and have the 5 yo in his Radian in the middle of the 3rd row (he wants to be a big boy and sit back there, he can buckle and undo his harness, and knows to only do so when I give him the OK) The van has airbags all over, but with the 3yo being on an outboard seat, I am guessing he would need the SICT protection more than my 5 yo since he is in the middle of the 3rd row and then more him into the Frontier when he reaches the harness limit on the Radian. With my kids being lean, he may be 16 before he nears that limit hahaha

So I'm here to ask, what do you think? Should I just return the SICT for a non SICT, switch the 3yo into the Frontier, or just leave it like it is? Mind you, the Frontier makes the 3rd row's comfort useless, I'd have to move it to an outboard seat to get anyone to sit back there to give them comfort.

If you switch it out for the non-SICT version and leave it in the back row middle, will anyone be able to sit back there next to the seat? If the non-SICT will allow passengers to sit next to it, I would exchange.

And yes, the SICT is HUGE!

I think the SICT is just over kill. I don't get the necessity. But I have a regular FR85 and that is big enough, Adding the SICT to it, Must make it huge! I would trade it in.