Last month Canterbury defender Mel Clewlow said Holcombe’s strategy was unsustainable, and that “anybody that flashes a chequebook will turn heads”.
Holcombe chairman David South explained the club needed “a boost” to reach England’s Premier Division.
The Rochester-based club’s women’s side are currently top of the Conference East, which is one tier below the Premier Division.
“I got approached by Holcombe and I like what they are doing,” goalkeeper Hinch, who has won 21 caps for England, said.
“They are a big club and they just need a little bit of a push to get up there.
“It is difficult to get out of these leagues and they’ve decided to go and look for players to help them do that. I wanted to be a part of their journey.
“It is just different. We have to win week in, week out and I have a responsibility there.”
Unsworth, who helped Great Britain win bronze at the London Olympics, says that a fresh challenge was among her reasons for joining Holcombe.
“Holcombe have set their sights on wanting to do great things in the future,” Unsworth told BBC Radio Kent.
“They are in the Conference but they are on their way up. It is an exciting time to be part of the club.