I am a model kit newbie by comparison, but I have an LBX Hunter standing on my computer tower next to my acrylic G'raha standee (and LBX Fenrir in a box waiting for my next free afternoon). I think Danball Senki is the only "mecha" series to do digitigrade legs and entirely cosmetic (and floofy!) tails (just not in the kits T^T), but the other obvious aesthetic source besides Custom Robo (which is more based on action figures a la G.I. Joe than model kits) is probably Mega Man, which has definitely done a number of beastly hybrids and also tends towards human faces. Notably, Howling Blade's arms aren't even jointed like a robot's, they look metallic but bend naturally at the elbow, so I think that disqualifies him as a Gundam already. That's some new-model Reploid nonsense right there. Or someone got lazy with the rigging.
I never got into Seed, but the MGEX Strike Freedom does look really cool.