No, the sole function of a settlor is to establish the trust.
Once the settlor pays the settlement sum they have no further involvement with the trust.
Nothing of substance generally turns on who the settlor of a trust is and the financial position of the settlor (or their related entities) is of no consequence in relation to the trust.
The settlor is a factual aspect as at a moment in time, analogous to the date on which the trust is established, and therefore cannot be changed.
Given that it is likely that any attempt to change a settlor will have adverse trust law and tax consequences, and will require court approval to be a possibility it is generally best to test why it is being suggested the settlor should be changed and what benefits is it hoped will be achieved.
If the settlor is someone who it was intended should also be a beneficiary of the trust please contact us and we can provide a suggested scope of work and fixed pricing to assist.