(Reuters) – Conflicting cultures and management styles are overshadowing Barrick Gold Corp’s $18 billion bid for rival Newmont Mining Corp, becoming factors just as important to the deal’s success as whether or not the pair’s lucrative assets in Nevada and elsewhere fit well together.

Mudslinging started almost as soon as the hostile all-stock, no-premium bid was announced on Monday. One rival executive compared the tension between Barrick Chief Executive Mark Bristow and Newmont CEO Gary Goldberg to the Hatfields and McCoys, two 19th Century U.S. families whose members held a grudge for generations.

“Newmont shareholders shouldn’t risk what they have and need for what they don’t have and don’t need,” Goldberg told Reuters on Friday.

Newmont’s board continues to evaluate Barrick’s offer, Goldberg said. He reiterated what he had said earlier in the week that all options were on the table, including a Newmont bid for Barrick.

Bristow was not available for an interview on Friday.

At the heart of the debate is Nevada, where Barrick and Newmont have owned neighbouring mines since the 1980s. Newmont said it prefers a joint venture in the state, a plan which Barrick says would be too complicated and not financially beneficial to all shareholders.

The logic of combining the company’s Nevada assets seems clear to both sides, but the sticking point is control.

“If those fences and armed guards were removed, you’d have trucks from Barrick’s mine not drive hours to get to the crusher and roaster, but they would have to go two miles to Newmont’s,” said an person familiar with Barrick’s thinking.

Bristow and Goldberg were emailing each other as recently as late January about a potential Nevada venture before Bristow stopped responding, Goldberg said.

“I was hopeful that Mark, as another miner, would be able to sit down and do a (Nevada joint venture) deal as a point of logic,” said Goldberg. “But then he dropped a hostile, no-premium bid.”

Bristow, for his part, said in an interview earlier this week that Goldberg did not show up for recently planned meetings to discuss Nevada.

‘FIGHT TO THE DEATH’

Barrick, which two months ago closed a $6.1 billion buyout of Randgold Resources, has encouraged Newmont to ditch a previously announced $10 billion takeover of Canada’s Goldcorp Inc.

Barrick has historically relied on acquisitions for growth, amassing billions of dollars of debt that it has been working to pay down. Newmont in recent years has focused on organic growth and financial discipline, although the Goldcorp bid breaks with past practice.

Those divergent strategies would be hard to meld even in a friendly proposal, but become that much more difficult amid the culture clash, according to multiple investors and bankers, with the acrimony threatening to scuttle the deal as it did when the companies last tried to combine in 2014.

“Newmont will fight to the death to stay independent,” a banking source said.

Newmont’s shares have gained 39 percent in the past five years, compared to a 26 percent drop for Barrick’s stock and a 3 percent drop in gold prices.

Some Newmont shareholders question Barrick’s claim that the deal will generate more than $7 billion in synergies.

“We have no reason to have confidence in (Bristow’s) ability to manage such a vastly more-complicated company,” said James Rasteh of Coast Capital Management LP, which said it holds more than 100,000 Newmont shares.

Bristow said in an interview earlier this week that his record at Africa-focused Randgold speaks for itself. Some investors agree.

“Newmont is a company in need of a shakeup,” said John Ing of Maison Placements, which declined to say how many Barrick shares it holds.

BlackRock, a top-three investor in both companies, declined to comment. Flossbach Von Storch, a large investor in both companies, has said it supports a friendly deal but could not be reached for comment on Friday.

Newmont would have to pay Goldcorp a $650 million break-up fee if it pulls its offer. Ironically, that would be the only cash that would change hands were the Barrick-Newmont deal to move forward, irking some Newmont shareholders.

Antitrust experts do not expect any deal to face regulatory pressure.