Personally I tend to carry both but I don’t carry a fairway wood so have the space for the extra club. If I was you I’d probably be more towards the hybrid as I find it way friendlier and more functional than a driving iron. All depends on your abilities with both clubs and what it is you’re wanting from the club.

Ash,
I suppose your decision depends upon what you use the 3i & 21* for... and how often per round.

I've got the T-MB 716 3 (& 4) iron and tend to use it off the tee (not greatly confident with it off short grass but OK from light rough) on tight and/or dog-leg holes (particularly those that bend right), so, personally, I'd stick with that.

My hybrid is 17* & has its own place in the set-up as I only carry driver & 3 wood.
If you use your 21* rinky-dink a lot, probs dropping it softly on the green from distance, then you might opt for that.
JT

Definitely see your point!! The t mb does come in lower into greens so 21 hybrid a good option for approach’s.

The t mb is great for tee shots and green attacks which need a bit of movement in the ball flight but with my swing putting bend in the ball can be dangerous!!!!

I’ve got a 818h2 hybrid in my bag, it’s perfect for over 220 /250 yards.
My 4 iron good for 210/220 yards.

A good ole 913H 21 does the trick for me.

For me - I chose the trusty 2 iron over a 19* five wood. I switched to this about 14 years ago my junior year of high school golf. At the time it was specifically the 695 z bladed 2 iron with an x100 shaft. I did it to give myself a reliable, low penetrating iron shot off the tee. I currently have the 718cb 2iron with a px6.0 shaft in it but I am strongly considering purchasing a t-mb 2 iron. To answer your question though - driving iron the whole way as I feel like they are more versatile to me in regards to trajectory (but I never could flight a 5 wood).

Good question. You might want to use both and swap them out depending on what kind of course you're playing on a particular day.If you have a lot of forced carries, use the hybrid. If you don't and want the ball flighted down, use the long iron.