The half-backs helped Ospreys reach the top of the GUINNESS PRO12 table, though the Welsh region have since fallen to second in their absence, while they are also the division's top-scorers with 237 points.
The pair reunited to help Wales beat South Africa 12-6 at the weekend, prompting head coach Warren Gatland to talk up their World Cup chances.
And Howarth believes the telepathy Webb and Biggar have developed at the Liberty Stadium is paying dividends for the national side.
"I really like Rhys Webb, there's something about him, he's really put his hand up," said Howarth, formerly of Newport Gwent Dragons.
"The reason Dan Biggar is getting the time he's getting is that Webb is so lively around set pieces and the ruck, so defences have to hold on. And if they don't he's gone, as he showed against Australia with his dummy-go.
"So when you've got someone like that allowing you the time it makes it a heck of a lot easier for a No.10.
"With those two, the combination they've got at the moment, I really like it. And it's a combination at club rugby as well for the Ospreys, so it can only benefit Wales."
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