YeeHawSoldiers can travel long distances the quickest on the team using jumps and scouts are better at travelling short distances quickly to finish players off. This means soldiers are the best class for taking space and punishing overextending players, therefore they set the pace for your team.
This is why the most effective soldiers nowadays are super mobile since if you are grounded you get outmaneuvered and picked off.
soldier is also the class with the biggest mechanics differences between low and high invite right now, from what i see.