varying sizes choice for same range of product

Hi everyone, Good Monday ! :)

Wanna ask for some opinion.... i'm interested to dropship some ladies & kids wears.
One thing I found out is that there are different sizes from sku to sku.

E.g for kids winter wear, sizes are 5T, 4T, 3, 2 and 1, for another similar wear product, we have s, m, xl, xxl
then another one, 3T, 5, 6T, 8T and so on.

Any feedback on how to manage the sizes so our store will look better. Cuz when customers
browse our product from one to the other and see sizes stated is such a way, it looks kinda
messy and suspicious lol !

Thanks for sharing !