Well shares can't be created out of thin air, so even if it's issuing new shares it will dilute ENIC's holding.
Agree that that valuation is absurd. Forbes' number is a rough estimate, but they're not going to be wildly inaccurate.
Given than loans now count against our PSR, it'd be pointless to bring in a capital injection of loans which put us to the sword. Zero double the authorities will treat us like Everton rather than City/Chelsea in terms of FFP and make an example of us.
Staying on the good side of PSR means we can inject £105M counted across 3 seasons. We're currently ahead £5M, so could actually bump that to £110M. At the £2.6B valuation, that's about a 4% stake. There's probably some creative accounting that can be done shifting assets with "debt" from THFC's books, including stadium naming rights, other sponsorships, etc. that can get you to a 9% stake for ±£250M that can be funneled directly to the squad.
But there isn't going to be a way to funnel more than that. If they're going to take on a larger share, and the plan is to use their money to fund the squad rather than provide Lewis more liquidity (entirely possible this is the actual goal), then it has to be a structured agreement spread out over the next decade.