If it's a matter of time to plant (not space, or knowing where to plant), and if you are planting mass quantities of say, 1 year old black locust with roots only a foot long or so, and you are attempting to do so very quickly, check your tools and technique. The dibble bar method works well. Here is one example from an Alabama Extension:
Source:
https://www.aces.edu/blog/topics/forestry/planting-southern-pine-seedlings/
If you don't have a dibble bar, a nice straight spade works just fine.
Even if you don't use this exact method (there are others, and I've used even fewer and sloppier spade motions for planting black locust), just try to get good root contact and avoid air pockets, then heel in the weird divots, and the black locust will probably do just fine being a pioneer plant if it has adequate water.
To give you an idea of how fast it can take to plant a bare root black locust tree, in the time it takes to have read this post, a couple trees could have been planted in average soil.