The French striker said: "In Lyon I played and scored and that goal came at a good time but I'd already scored four in the league.
"At Rangers we have many players, including five attackers for one or sometimes two places. Sometimes I must agree to find myself on the substitutes bench but that forms part of my job."
Cousin concedes his career was on a slippery slope after falling out of favour at Lens but he's found his calling at Ibrox and it excited about the future under Smith.
He said: "The last six months were difficult in Lens and I know the reasons for that. After there I needed to rebound and I have fallen into the ideal club by arriving here. There are a beautiful series of matches to come with the two games against Barcelona and there is Celtic, too."