(a) Except as provided in subsection (b) and except as provided in connection with the share of the surviving spouse who elects to take an elective share, shares of distributees abate, without any preference or priority as between real and personal property, in the following order: (1) property not disposed of by the will; (2) residuary devises; (3) general devises; (4) specific devises. For purposes of abatement, a general devise charged on any specific property or fund is a specific devise to the extent of the value of the property on which it is charged, and upon the failure or insufficiency of the property on which it is charged, a general devise to the extent of the failure or insufficiency. Abatement within each classification is in proportion to the amounts of property each of the beneficiaries would have received if full distribution of the property had been made in accordance with the terms of the will.
(b) If the will expresses an order of abatement, or if the testamentary plan or the express or implied purpose of the devise would be defeated by the order of abatement stated in subsection (a), the shares of the distributees abate as may be found necessary to give effect to the intention of the testator.
(c) If the subject of a preferred devise is sold or used incident to administration, abatement shall be achieved by appropriate adjustments in, or contribution from, other interests in the remaining assets.