I think it's more to do with their coloration that brings people to mind of Pulseman. Ledian's head is red and face is yellow, such as Pulseman's face, additionally its eyes are blue as is Pulseman's visor. Though it lacks the V-shaped crest that Pulseman wears on his torso, Pulseman's body is also beige and red. Lastly, both have dark skinned ligaments (arms, legs), and Ledian's hands are white, such as Pulseman's gloves. The colors of Ledian here are pretty specific. Yes it's also because Ledian is chiefly based on a ladybug, but the similarities are there. If Ledian were more based on general toku heroes without Pulseman in mind, I don't think it would look nearly the same, or wind up being a different bug altogether.