I have decided to go ahead with the switch this weekend as far as square-cell pieces are concerned. The names new to Man and Beast will be as follows, with non-coprime components usually Leaping unless marked $, in which case they are usually Stepping.
Frock=Cross+Trechick - replacing Tadpole
Gardener=Point+$Dabchick+$Trechick - new
Guardian=Wazir+$Dabbaba+$Trebuchet - piece new to MAB
Lining=Gardener+Restless - new
Liondog=Guardian+Wrestler - piece new to MAB
Newt=Elephant+Trebuchet - replacing Rosette
Nuke=Tusk+Trechick - replacing Rosebud
Restless=Cross+$Tusk+$Trisk - new
Toad=Dabbaba+Trebuchet - replacing Treader
Toke=Dabchick+Trechick - replacing Trekker
Vestment=Mitre+Trechick - replacing Maypole
Wrestler=Ferz+$Elephant+$Tripper - piece new to MAB
A few brand new 3d and/or hex ones will get in as well, namely
Garage=Gardener+Wether
Guarantor=Guardian+Weatherer
Liner=Lining+Wether
Liontamer=Liondog+Weatherer
Lucky=Key+Lurch
Reckless=Restles+Wether
Weatherer=Viceroy+$Eunuch+$Zombie
Wether=Saltire+$Key+$Lurch
Wrecker=Wrestler+Weatherer
Zookeeper=Eunuch+Zombie
I am postponing adjusting cubic Amphibian pieces to consider the fact that different pieces are Amphibian in different geometries. The Toad and Newt are Amphibian in all geometries that have them (2d hex has no Frog or Newt), but the Frog has an unbound component in hex-prism. The Vicbaba is Amphibian in 2d hex but Viceroy+Trebuchet, which is Amphibian on a cubic board, is bound to a third of a hex board. Any thoughts on dealing with other geometries, or should I just not bother with Amphibian-themed names beyond the square-cell board?