Personally, I would contact a fitter and try those irons to see how they feel with the right shafts. Want to make sure they are right for YOU. Just a friendly suggestion that could save you money down the road.

If you play MBs already and can be somewhat consistent with them, I think your idea is solid. Certainly get fit to find the right shafts, but the added forgiveness in the longer irons makes perfect sense.

Spieth and JT (among other Titleist pro players) are doing it with T100/T200s. As good as you may be, I doubt you are any more accurate than they are, and they realize a little extra forgiveness in the long irons is a good thing. If it's good for them, it should definitely be a good move for you, IMHO. T100s are definitely accurate irons in the right hands, so it's not like you'd be giving up anything by playing them in your long irons. More Titleist players on Tour use AP2s and/or the T100 series than use MBs to begin with.

T100 4 iron has been very popular the last year

I use ap3 4-7 and my 8 and 9 are my older ap2s. I like it for better control on distance and definitely recommend looking into it.best of luck

I'm a big fan of combo sets. Currently gaming srxn 585/785, but the new Titleist irons have my attention. So nice to have the feel of a precision of a forged iron for short irons. Thinner sole, better turf interaction. Really have control. But who doesnt need some help in the longer iron?. Im willing to sacrafice some feel to get the ball up in the air and going straight.

Combo sets are the way to go. A lot of pros do that for that same reason you mentioned, for some extra forgiveness in the longer irons. I play 620 MB and T100 combo set.

3-iron TMB
4-6 T100
7-PW 620 MB

I would agree with everyone and ensuring that you get fit for the correct shafts. Making sure that the lofts are gapped accordingly and the weighting of the irons feel good to go.

But you can't go wrong with a combo set, as you have the best of both worlds and having the MBs in the short irons and some forgiveness in the longer irons.