If you continue reading the article, it mentions that Russia had mobilized almost a million soldiers in the Far East by the end of the war, and that mobilization largely happened after the Battle of Mukden. Without the naval defeat at the Battle of Tsushima, Russia would have had the upper hand at that point, and the war would likely have reached a different conclusion.

Industrial armies were massive. By the standards of that era, current US military strength exceeds 60 million. But they mostly relied on reserves, which were slow to mobilize. Japan's quick decisive victories ended the Russo–Japanese war before it had a chance to escalate further, potentially reaching the scale of the Eastern Front in WW1. But even then, the Battle of Mukden was one of the largest land battles in history until that point