Marc Antony's facile dispension of one of the triumvirs is yet another example of his duplicitous and self-serving nature first evinced in his manipulation of Brutus in attaining permission to address the Roman pleblians, whom he then fomented into civil strife, a destructive war of Roman against Roman which his supposedly beloved Caesar would never have wanted as Caesar greatly loved Rome.
In Act IV, Scene 1, Antony, Octavius, and Lepidus compile a death list of their political enemies. After sending Lepidus on an errand, Antony addresses Octavius, Caesar's nephew, thus describing Lepidus,
This is a slight unmeritable man,
Meet to be sent on errands. Is it fit,
The three-fold world divided, he should stand
One of the three to share it? (4.1.13-16)
suggesting that Lepidus should be eliminated, also. As a counterpoint to Antony, Octavius disagrees, contending that Lepidus is "a tried and valiant soldier" (4.1.30-31). But, Antony cruelling equates Lepidus's virtues as equal to those of his horse because he must be led and taught and has no reasoning ability of his own. Antony further describes Lepidus as mere "property," to be used as he sees fit. Clearly, Antony is an exigent man, acting on what will serve his own interests. This character flaw is furthered developed in Shakespeare's Antony and Cleopatra when he puts his own prurient desires ahead of others to the detriment of Rome.