Possibly another reason PJ went with the nameless scrubbing bubbles and not liberated Gondorians as he (methinks) tried to keep the main characters in the light. Eomer gets short shrift; watch how he's treated in RotK, especially after Theoden dies. Eowyn, after killing the Witch King, still has to be saved from the limping Gimp by Aragorn, as killing the second-highest ranking baddie just wasn't enough.
So why add even more nameless, though prominent, characters?
Seeing men (and women, I care not) jump down from the ships, even with the scrubbing bubbles, would have been better, as it would have shown that Aragorn was becoming a leader of humans, not some sorcerer or elvish wight. It was he that led the men (and elves) to victory at Helm's Deep; at Minas Tirith, he could have got out his fishing pole and relaxed on the docks while his undead army did all of the work, securing
his new realm.
How many orcs did he cut down in comparison to his army? Did he tell them to go here and there, showing his battle acumen? Nope. He just let the ooze ooze.