From the discussions with the 4.5%, the reasoning there was they only needed to provide extra funding for 0.5% because the other 4% could be paid for using the additional £2 billion promised to schools in the Autumn 2022 statement for Sept 2023.
So they reckoned that 4% was on average affordable because of the extra £2 billion
This offer is expecting schools to afford 3.5% using the £2 billion and topping up 3% to make 6.5%. So it’s better funded than the 4.5% as only expecting schools to pay 3.5%, not 4%
They also acknowledge that some schools still won’t be able to afford 3.5%, hence the hardship fund.
By “afford” they mean be able to pay without cutting budgets elsewhere.
This is taking into account energy prices coming down from this year, so schools tied into expensive contracts will need to look at this.