Polygamist Leader Marries 2 Teen Sisters

Their names were Maria and Sarah Lawrence. In June, 1841, Joseph was appointed guardian of the minor heirs of the Edward Lawrence and trustee for them and of an estate of $3,831. In 1842 both girls begain living with Joseph and Emma in their home. In May of 1843 Joseph married both girls. He was 37 and they were 19 and 17 years old.

I have a problem with this. A 37 year old man taking 2 teen sisters as polygamist brides and he does so from a extreme position of power. He is their prophet, he is their legal guardian, and they lived with him in his home in Nauvoo. Is there some angle which this type of relationship should be considered acceptable? Here is a good summary of the situation:

In June 1841, Joseph Smith, Hyrum Smith and William Law had assumed the
responsibility of the deceased Edward Lawrence's estate valued at $7,750.06.
Joseph was named as guardian of the Lawrence children. Somehow during his period
of indecision, William Law found out that Maria Lawrence was sealed as a wife to
Joseph; in fact, Law, as he later stated, found Joseph in a compromising
situation with Maria on 12 October 1843. Two weeks later, 26 October 1843,
Joseph ostensibly sealed Maria for time to John M. Bernhisel, an outsider to the
Lawrence estate arrangements. But in January 1844, Joseph apparently felt this
would no longer calm the angered William Law. The day after Joseph and William's
final confrontation, Joseph began arrangements to relinquish the estate affairs
entirely. From the ninth to the twenty-third, William Clayton was working with
the Prophet preparing the transfer of the estate affairs to John Taylor.
Undoubtedly, if William Law, one of the appointed trustees of the estate, I
'claimed' that Joseph had not only extorted the funds of the estate, but had
also committed adultery with the eldest child of whom he was personal guardian,
that would make an explosive expose.... Law appeared before the first sitting of
the Grand Jury of the Hancock County circuit court to swear out charges against
Joseph. Law filed charges and presented such evidence that the Grand Jury
authorized an indictment against Joseph Smith for 'adultery and fornication.'
While Law made oath that Joseph 'live[d]...an open state of adultery and
fornication' with 'certain women,' the only woman he named was Maria Lawrence.
Law testified of two dates when Joseph Smith allegedly committed the illegal
acts—specifically the one date already mentioned, 12 October 1843, and the other
date 1 January 1844, the day Law began his diary("Joseph Smith's Introduction of
Temple Ordinances and the 1844 Mormon Succession Question, Andrew Ehat M.A.
thesis, Brigham Young University)

Todd Compton's In Sacred Loneliness describes it this way:

The marriage to the Lawrence sisters became public knowledge when William Law,
Joseph's second counselor in the First Presidency, became alienated from the
prophet......On May 23 he filed suit against the Mormon leader in Hancock County
Circuit Court, at Carthage, charging that Smith had been living with Maria
Lawrence 'in an open state of adultery' from October 12, 1843, to the day of the
suit. In response, Smith flatly denied polygamy in a speech delivered on May 26:
'[The charges against me are false].....What a thing it is for a man to be
accused of committing adultery, and having seven wives, when I can only find
one.....[I can prove them all perjurers.]' As polygamy was illegal under US law,
Smith had little choice but to repudiate the practice. (In Sacred Loneliness:
The Plural Wives of Joseph Smith, pp. 476-477.)

From the FARMS Review of Compton:

The Lawrence sisters continued to live in the Mansion House after the Partridge
sisters moved to other Nauvoo homes. In Sacred Loneliness mentions several
reliable documents indicating that Emma approved and was present when Maria and
Sarah Lawrence were sealed to Joseph Smith (see pp. 743–44). So the author's
tentative conclusion is puzzling: "It is entirely possible that she gave her
permission for these marriages, as Emily asserts" (p. 475). The Lawrence family
was converted in Canada and moved to Illinois before the father died, after
which time Joseph Smith was appointed guardian of the children who had not
reached legal majority. The Prophet managed the whole estate under court
supervision. Ex-Mormon William Law gave exaggerated figures in later accusing
Joseph Smith of mismanagement