Plasmas, and the states of matter, are more of a convenient categorical heuristic than actual things. We categorize matter as so, so we can conveniently convey information about a material's conditional properties, but any material can be a solid/liquid/gas/plasma under the right conditions...
But a solid is not a plasma, as by definition a plasma also has properties of a gas. So a solid metal is not a plasma even if they share some properties. In other words, a plasma is not a solid, and so "solid plasma" is a kind of an oxymoron.
To really drive the point... any metal can be in either the solid or plasma states, so thinking of them as "solid plasmas" isn't really correct.
"Solid chunk with electrons free to conduct through it" and "gaseous chunk with electrons free to conduct through it" are pretty similar. Sure it's technically an oxymoron but really rather close to accurate. Maybe pedants would be happier with "solidified plasma".
Not really... I mean, the issue starts with the equating of 'metal' to mean 'solid', let alone how 'solid' is a bit of an oxymoron for 'plasma'. Additionally, all materials are free to conduct electrons through it, in solid, liquid, or gaseous forms (the differences are just in the energy/distance thresholds in order to do so). So "Solid chunk with electrons free to conduct through it" doesn't quite grasp what metals actually are. I mean, you can have solid chunks of oxygen with electrons free to conduct through it, given the right conditions, and oxygen isn't a metal. But then again, this is entirely a matter of an arbitrary line we've chosen to categorize matter for convenience and communication purposes, and we call those conditions for elements like oxygen "metallic", so if it helps comprehend things then I don't see anything wrong with that.
But a solid is not a plasma, as by definition a plasma also has properties of a gas. So a solid metal is not a plasma even if they share some properties. In other words, a plasma is not a solid, and so "solid plasma" is a kind of an oxymoron.
To really drive the point... any metal can be in either the solid or plasma states, so thinking of them as "solid plasmas" isn't really correct.