You can tell the relative size of each tribe by the size of their territory and the number of cities they received. In this passage, Issachar received 16 cities and Asher 22. Issachar’s cities were largely unknown, but Asher’s include cities that had future significance in the life of Israel. It included Carmel, which was the location of the future showdown between Elijah and the prophets of Baal, where God answered by fire. It also included Beth Dagon (House of Dagon), an obvious reference to the Philistine god. Both of these cities were steeped in idolatry, and it would plague Israel for years to come.
Two things come to mind here. First, when God instructed Israel to take the land, he to;d them to drive out all the inhabitants. Israel did not obey, and that is why idolatry continually haunted the nation. Second, the people did not know what would face them, or how significant the cities in which they dwelt would become. Always anticipate that God can do something great, even in your house!