>>could a good argument be made that the equity in the home gives parity in retirement. to the pension in payment ,as some of the money could be released .
No. A court would give short shrift to such an argument and so would most solicitors. Pensions and equity are two different asset classes like apples and pears. That is not to say that spouse A might not agree to let have spouse have more of the equity in return for not having a pension share but that is rather a different argument. Also whether that sort of substitution works depends entirely on the figures.
If, say, the total equity is worth £300,000 and spouse A has a pension with a capital transfer value of £100,000 and spouse B has no pension then spouse A might agree to spouse B having £200,000 of the equity in return for making no claim on the pension. However, using the same £300,000 equity if spouse A has a pension with a capital transfer value of £500,000 there is no way that spouse B's right to a pension share can be bought out with more equity. There simply isn't enough to do it or get anywhere near.