i would promote the left one ....

remove the smallest immediatley ...

shorten the right one in half for a year or two ...

every leaf is a food making machine.. and with this small a tree.... dont go cutting off half the leaves and expecting much growth ...

tree time is counted in decades.. pruning happens across many years ... there is no real reason to do all your pruning one afternoon.. on babe trees .. big trees.. whatever. .. they have huge root masses to offset whatever you do above ....

i would expect more growth for a maple in 2 years ..

want to discuss why yours seems to be in slow motion.. if so..where are you.. big city name..

is the grass that brown all summer.. or is that winter color???

how did you plant.. what is your native soil.. and how do you water ...

ken

ps: what are the plants out beyond the curb.. in the street??? .. is there a story there?

as to your title specifically.. pruning rules dont change based on the type or name of a tree ... giving us the name helps.. but rarely changes the method ...

ken

IMO, with 30 years professional experience doing this, the tree is too small to start any significant pruning. Structural pruning - which all decurrent tree species benefit from (yes, species does make a difference!) - should be initiated early in the tree's life but there is no overt need at this stage and I would wait until the tree reaches around 5' in height or has some significant trunk elongation before jumping in with my pruners and whacking off branching the tree needs now to encourage more healthy growth.

Patience is a virtue!! Especially in gardening 😊

.... agree with Pam. The only thing that's important at this point is deciding if you want a stick straight (formal) trunk or one with movement; and if you want a straight trunk, taking whatever step(s) might be required to make it happen before it will be difficult to make happen. If you want a shrubby tree (one trunk but with several low branches serving as subordinate trunks, you needn't do anything yet.

Below, you'll see A palmatum with movement purposefully added to what was initially a straight (formal) trunk. You can see I wired a branch to a more upright position to be the new/ future leader. The right, and thicker half of the bifurcation, what most would call the trunk, is actually serving as a sacrifice branch; i.e., to add strength/ thickness/ taper to what will end up being the trunkline. It will not be a part of the tree and will eventually be severed just above the smaller wired branch when its work is done.

An aside: this tree was a seedling and had really ugly roots, so it was layered off of it's original root system.

If you look closely, you can see the tourniquet wire (beneath the new root system) and the old roots under the new root system.

The part about the roots doesn't really play into the topic excepting it illustrates you can bare-root and correct root issues before planting out, or if the tree has only been in the ground for a year or two, with little to no fear of jeopardizing the tree's viability. It's better to suffer the minor setback (in growth rate) caused by digging the tree up, correcting root issues, and replanting it, than to take a chance that comes with removing a plant from a nursery can (or pot) and dropping it into a planting hole (if that's what you did).

The fastest way to fix your quandary, if you want a straight trunk, is to lift the tree and change its planting angle and stake it. You could also, at the same time, correct any problem roots that are almost certainly an issue waiting to occur (if you didn't bare-root and correct before originally planting it), and make sure the planting depth is appropriate.

Al

Just to add: I agree, there's no hurry to prune anything at this early stage. Let the tree put out as many leaves as possible the first year or two so it builds a strong root system.

Maple branches up to 1" in dia. can be removed no problem sometime down the road.

Shantung maples are an ornamental tree with a maximum mature height of ~25', so pruning will be somewhat different than it would be to a large shade tree, that will have 6-8 ft. of exposed trunk.

Thee most important thing now, make sure the tree is planted at the proper depth. If the root flare is buried to any extent at all, you must correct that as soon as possible (according to you climate).

And as Al said, this will be a good time to make sure there are no other root tangling problem and an opportunity to straighten trunk direction if needed or desired.