Complex sentence: Hays hoped to lure out around fifty of the Mexicans but when the Texans were spotted, 200 Mexican cavalrymen were sent after them followed by forty Cherokees and about 300 more men led by Woll himself.
Split into simpler sentences: Hays hoped to lure out around fifty of the Mexicans. But when the Texans were spotted, 200 Mexican cavalrymen were sent after them followed by forty Cherokees and about 300 more men led by Woll himself.