What does Judges 5:15 mean?

'The princes of Issachar were with Deborah; Issachar was with Barak, rushing into the valley at his heels. But in Reuben's tribe, there was a lot of soul-searching.' Judges 5:15 - Modern Text Bible

(Issachar fully supported the fight, but Reuben hesitated, torn between joining in and staying back.)