But intra-team tensions have subsided significantly since Rosberg's shock retirement paved the way for the arrival of Bottas from Williams, while the resurgence of Ferrari has given Mercedes an external enemy to fight against.
Wolff praised Bottas for having run Hamilton close in 2017 so far, calling the Finn's qualifying results a “pretty strong record against the fastest man on the grid”, but said the surprise element was the team harmony.
“Valtteri for me is performing up to our expectations. When we decided to take him we knew about his qualities,” said Wolff.
“So on track he has met our expectations and it's getting better every race, and he progresses every race, which is very nice to see.
“But where he has exceeded our expectations, and both of them have actually, is how they work together.
“They get on with each other, and respect each other, on track and even more off track. It's very straightforward.
“It came to a point in Silverstone when Lewis said: ‘I'm going to pull him along with me.'
“It's just an underlying respect for the other individual and the other race driver.
“Have you seen that in the past in a team, where the two guys got on like this?
“The personal relationship between Valtteri and Lewis is totally different than what it was between Nico and Lewis.
“The working relationship is just in a totally different league, which carries over into the dynamics within the team, because everybody is affected in a positive or negative way.”
The build-up to 2017 had not been straightforward for Mercedes – with F1's major change in regulations coinciding with Rosberg's sudden departure and the transition in technical management from Paddy Lowe to James Allison.
While Mercedes is not currently dominating F1 the way it had in the preceding three years, Wolff feels the team has coped well with the challenges of the year so far.
“A certain factor of disruption is not negative,” Wolff said.
“I would say I'm happy with our performance. Because if you would have said to me in the winter that we would win six races and have eight pole positions (before the break), I would have taken it.
“But then it was more difficult than the results look like, because we had some pretty close racing with Ferrari – Barcelona with Sebastian (Vettel) being really close behind Lewis, and then Sochi and Spielberg, being really close behind Valtteri.
“All in all, I would say we have done OK, considering there were so many changes.
“We knew how difficult it would be to stay competitive through such a major regulatory change, because it hasn't been done before.”