Down came the rain and in rained the goals. Walter Smith ended a sodden afternoon at Ibrox drenched in affirmation of Rangers' attacking potential, yet insisted significantly greater fluency still lay ahead.

In several aspects Rangers can consider themselves well ahead of schedule. When Steven Whittaker completed his £2m move from Hibernian last month, Smith expressed hope that, given time, he would form a dynamic partnership with Alan Hutton on the right flank. The Ibrox manager was probably talking in terms of weeks, but it took only minutes of Whittaker's debut for the rewards to be seen. The synergy between the two Scots was an immediately attractive feature of Rangers' output and their capacity to seamlessly interchange offers a different dimension to Smith's set-up.

It was perhaps most clearly apparent when Hutton fed Whittaker to supply the cross for Rangers' fifth goal against a Falkirk outfit whose late collapse buried a previously enterprising performance. The Ibrox pair gleefully celebrated what may represent the start of a very fruitful relationship.

Whittaker even had the bonus of a goal, albeit one via a deflection off the boot of Kenny Milne, to underline what he can bring to the party His delayed introduction to the side has been one indication of the heightened strength of the Rangers squad. Another is the fact that DaMarcus Beasley and Brahim Hemdani, who both featured against Red Star Belgrade in the Champions League qualifier, did not even make the bench against Falkirk. That may have been due to the Scottish Premier League's under-21 rule, again lambasted as "ludicrous" by Smith, yet it has been some time since an Ibrox manager was able to be so choosy when selecting a squad.

Kirk Broadfoot was among the substitutes and later joined Whittaker in the unlikely scorer stakes after replacing Nacho Novo to play the final seven minutes as an auxiliary left winger. The former St Mirren captain emphasised the intense competition for places.

"It's the biggest squad I've seen and there are maybe 30 players who could come into the first team and do a job," said Broadfoot, who described his first Rangers goal as "a dream come true".

"Obviously, the Under-21 rule takes out three players straight away, but it's a battle to make the bench never mind the starting line-up. Everyone over the course of the season will play their part for Rangers."

Daniel Cousin offered evidence that his part could be vital. The Gabon striker's £1.1m fee could soon be entered into the bargain category after he made it three goals in three appearances, displaying a sweet blend of power, mobility and accurate finishing. Cousin even had the good manners to set up Kris Boyd, a particularly hungry substitute, for the strike which ended his mini-famine and, with it, some of the more outlandish debate about his place in Rangers' pecking order. Jean-Claude Darcheville matched Cousin's double after replacing him for the final 10 minutes, thereby ensuring all of Rangers' first team forwards have troubled the scoresheet inside the opening three SPL games.

"It's very pleasing to see all the strikers in among the goals and Kris Boyd helped create another one," said Smith after his team maintained their 100% start to the season. "We're just getting to know Daniel Cousin as a player but he is showing he can be a valuable asset.

"We have managed to win the games, which is very pleasing, but we're still a fair bit away from where we want to be. You can't just throw a team together to play in the perfect manner. Maybe at Real Madrid, but not here. We're happy with the steady progression being made."

Cousin tapped over the line inside two minutes after Lee McCulloch and David Weir had gone close from a Barry Ferguson corner. Whittaker doubled that advantage before Rangers conceded their first goal of the season. It's doubtful they will leak a better one.

Arnau Riera was once captain of Barcelona's B team and the Falkirk midfielder exhibited the class more commonly associated with the Camp Nou by arrowing a glorious 30-yard strike into the net off Allan McGregor's right-hand post. It was no more than John Hughes' side deserved at that stage for their intricate possession.

Cousin slammed in Rangers' third early in the second half, after Novo's fresh air swipe left him red-faced on a long desired appearance from the start, but Graham Barrett again reduced Falkirk's deficit to a single goal. The Irishman's neat dink over McGregor confirmed the end of a traumatic two-year recovery from knee ligament damage.

The final 15 minutes were, though, a procession towards poor Tim Krul in the visitors' goal. Boyd wheeled to bury Cousin's cross, then hit the post with a header to allow Darcheville to knock in his first. The former Bordeaux striker thumped his second after a forward thrust from Ferguson before dabbing a pass for Broadfoot to score with the aid of a nick off Steven Thomson.

A 4-0 thrashing of Gretna on the opening day has been followed for Falkirk by the grim shipping of 11 goals in two games against the Old Firm. Hughes did a good job of remaining positive, but admitted concern at the signs of mental fragility among his players.

"I have to make sure that the boys don't feel sorry for themselves," said the Falkirk manager. "I thought that some heads went down when Rangers scored their fourth. It was the same in the Celtic game last week.

"If you have pride in yourself and your club, you should keep going and try to keep the score respectable. That was disappointing. It was a day when our squad was asked a question and I think that one or two players let themselves down."