Hamilton's 2015 paper summarized data indicating that Venus and Mars, like Earth, had fractionated crusts, mantles, and cores very early, but, unlike Earth, both preserve on their surfaces an ancient bolide-bombardment history like that of the Moon.
Both Venus and Mars show in their surface geology the acquisition of huge volumes of water delivered by bolides late in their major-bombardment histories, hence about 4.0 b.y.