was it 3000-some ethnically homogeneous people?

That's a tricky question... because at the time, the Irish were considered not the same ethnicity, and in some important ways, not really "white."

So for the people aboard, lots of the folks in steerage (a whole book's worth) were of a different race. (Edit to add: The same social perception would extend to the Italians in the restaurant staff, and the Turks in steerage - see this old discussion and this one for more on whiteness in the early 20th century.)

More to the point of what you're asking, though, Encyclopedia Titanica has an interesting thing on eight Chinese sailors who'd booked passage on Titanic because they couldn't get work in England and were returning home to Hong Kong (via New York and Cuba). Two of them died, the other six were detained by Immigration in New York and shipped to Cuba the next day - they were all traveling on one ticket, and four or five of them were described as "stowing away" on lifeboats.

One, though, Fang Lang, was possibly a little bit of a hero:

Second Class Passenger: Charlotte Collyer:

A little further on, we saw a floating door that must have been torn loose when the ship went down. Lying upon it, face downward, was a small Japanese. He had lashed himself with a rope to his frail raft, using the broken hinges to make the knots secure. As far as we could see, he was dead. The sea washed over him every time the door bobbed up and down, and he was frozen stiff. He did not answer when he was hailed, and the officer hesitated about trying to save him.

"What's the use?" said Mr. Lowe. He's dead, likely, and if he isn't there's others better worth saving than a Jap!"

He had actually turned our boat around; but he changed his mind and went back. The Japanese was hauled on board, and one of the women rubbed his chest, while others chafed his hands and feet. In less time than it takes to tell, he opened his eyes. He spoke to us in his own tongue; then, seeing that we did not understand, he struggled to his feet, stretched his arms above his head, stamped his feet, and in five minutes or so had almost recovered his strength. One of the sailors near to him was so tired that he could hardly pull his oar. The Japanese bustled over, pushed him from his seat, took the oar and worked like a hero until we were finally picked up. I saw Mr. Lowe watching him in open-mouthed surprise.

"By Jove!" muttered the officer. "I'm ashamed of what I said about the little blighter. I'd save the likes o' him six times over, if I got the chance."

Hard to say because not everyone got his name... and there was at least one actual Japanese passenger, Masabumi Hosono, but he was on a different lifeboat, and didn't seem to do any rowing.