early 15c., "meat or fish market," from schamil "table, stall for vending" (c. 1300), from Old English scamol, scomul "stool, footstool" (also figurative); "bench, table for vending," an early Proto-Germanic borrowing (Old Saxon skamel "stool," Middle Dutch schamel, Old High German scamel, German schemel, Danish skammel "footstool") from Latin scamillus "low stool, a little bench," ultimately a diminutive of scamnum "stool, bench," from PIE root *skabh- "to prop up, support." In English, sense evolved from "place where meat is sold" to "slaughterhouse" (1540s), then figuratively "place of butchery" (1590s), and generally "confusion, mess" (1901, usually in plural).
<a href="https://www.etymonline.com/word/shambolic">Etymology of shambolic by etymonline</a>
Harper, D. (n.d.). Etymology of shambolic. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/shambolic