Legend behind the MacLachlan Coat of Arms

There is an old Scottish tale behind the MacLachlan Coat of Arms. Legend has it that the reason behind the two roebucks (deers) supporting the MacLachlan Chief's Coat of Arms came in 1249, when King Alexander II made his great show of strength in Argyll, he ordered the local chiefs to send their money (taxes) by the fastest messenger, and Lachlan Msr (the younger) tied the moneybags to the horns of a roebuck. In wonder if this was a statement by the MacLachlan chief about paying taxes. Deer's are fast but not exactly reliable transport.