The 31-year-old striker is expected to make his Robins debut alongside Hayles against Huddersfield Town on Saturday following his deadline day arrival from Yeovil Town.
"We will be a little and large combination and I've always had that throughout my career," he told the Gloucestershire Echo.
"I played with DJ Campbell and Isaiah Rankin at Brentford and everywhere I have been I had a little man.
"Barry is more of a nippy player, who will get the ball into feet while I can provide hustle and bustle and tire out defenders."
The Town manager Keith Downing has aso extended the trial spell of French midfielder Kevin Tunani to take in a reserve team game next week.