Assuming we end up with ARL taking a 51% hold at the project...

Assuming we end up with ARL taking a 51% hold at the project level and retains operation then they'll need to fund 51% of the capex. In practice what this means, using very round numbers of say a $3bn capex is that they're up for $1.5bn which would typically be a funding mix of 60:40 debt and equity. Given the size of this deal and the likely interactions with the various ECAs and government agencies, including the ability for the large Japanese corporates to lean heavily on their own commercial banking arrangements in Japan (SMBC, MUFG etc) there will be no issues IMO with the debt portion of the funding. ECAs will also provide what they call "covered tranches" of debt which effectively guarantees or cash-backs the debt provided by the commercial banks meaning those banks ultimately only take on government risk, not project risk, and hence the margins are much much lower.

Let's also assume that the share price of ARL should make a large move northward before any required equity raising for the 40% mentioned above. Let's again say for round numbers SP is a $2, the 40% of $1.5bn of equity required is ~$600M which at $2/share is only 300M shares (disregarding costs, fees etc).

There is also plenty of precedent with these types of transactions (Liontown was a good one pre all the equity games) where the offtaker provides additional offtake financing to secure the end product. This can take the form of pre-payment, working capital facilities etc and given the life of this project may be able to be repaid over a very long term or repaid via lower cost product for a period of time and may be structurally subordinated to the senior debt holders, hence treated like equity.

If these Japanese corporates do sign up, do not worry about funding. It will happen.