You can plant many monoembryonic mango seeds and the seedlings can have nearly identical growth habits and even their fruit may be indistinguishable. But, you can also have a seedling that is completely different. It just depends on what pollinated it. Was it crossed with a completely different type of mango or was it selfed( pollinated with its own pollen).
Even if it was selfed, it can have very different phenotype than the rest of the group, it just depends a lot on how set the traits are. The more selected a trait or the more likely it is for that trait to show up.
For example, if you cross a Carrie and a Julie mango, both of which have a close family tree, you will more likely see a phenotype that is similar such as more compact growth or the fruit may have that kinda spicy note that the parents have.
Simon