Ordinarily, it should have been impossible to enter the Speed Force so easily. Besides, there was no ceiling above this track, so it was even less possible for Mexicans to fall from the sky.
But none of that was a problem for Deadpool. He had his own rigorous logic.
The Speed Force Plane had originally been a circle, a circular racetrack. It should not have stretched infinitely as it did now, trapping everyone inside.
Though they still did not know what method their enemy, that Goddess, had used, since she had altered space, Deadpool could make use of that.
When the other side refused to follow the rules, he would be even less willing to follow them. The Time-Space Belt might have been broken, but the Plot Continuity Gem could still be used.
As for why Mexicans could fall from the sky, that was even simpler. They were illegal immigrants and possessed the special trait of "illegal entry." Since they could sneak from Mexico into the United States while risking border immigration officers emptying their magazines into them, they could sneak into anywhere.
To Deadpool's cancer-riddled brain, this was entirely logical.
He spoke to the Mexican in Spanish again. No one present except Batwoman understood a word, but that did not matter. The illegal immigrant nodded repeatedly and soon vanished abruptly once more, just as he had appeared.
"Will this really work?" Barry was somewhat doubtful. It was not that he worried Deathstroke could not handle it; he just found Deadpool a little unreliable. "The strange thing is, I actually find all this pretty reasonable. I just wonder why your speed dial contacted a random Mexican instead of Slade."
"Sigh, looks like I should start thinking about retirement. I truly cannot understand the things young people play with these days."