A number of questions are related to using SSH with Windows terminal
and a few others are related to opening multiple, equal sized panels side-by-side. None of these questions actually offers an answer to achieve the desired result (see title).
Some outdated answers say it's not possible, but after a recent update it now should be.
This answer explains how to open multiple equal-sized panes side-by-side. However, it does not explain how to execute a command within those newly opened panes.