Sometimes I want this, other times I prefer random sizes.

For example, with tomato based sauces, I often have left overs. For those, sometimes it is not enough so I might add extra crushed tomato to the left overs.

Yet I won't cook that as long as the original dish. So I effectively end up with crushed tomatoes cooked to different amounts.

And you can taste it. It widens the flavour. Gives more depth. Since I noticed this, I often hold back a tablespoon or two of crushed tomatoes, giving long, short, and fresh tomato flavour. The fresh amount added is tiny, like adding spice!

For some dishes, I add fresh garlic but a tiny bit of garlic powder. Just a subtle hint of a slightly different garlic flavour.

Back to onions, different sized pieces cook more/less, and create more variance in flavour, as long as the cook isn't so long to completely cook them all.

I also like adding more than one type of onion to a dish.

Anyhow. Widen those flavours!