My headcannon is that the Goon variant of the Lion was actually just a Clan variant for the Horses and secondline forces in any other Clans that needed to move vehicles between worlds. Clanners didn’t want to waste resources on a special-purpose Dropship for moving dezgra vehicles, so, like you say, they shuffled cubicles around on old Lions. But the MUL doesn’t agree.
I’m also skeptical of the MUL’s claim that the 3005 variant of the Goon Lion is present in every era. Presumably, the Goons would have switched over to the 3052 variant sometime after, you know, 3052.
A Clantech “Lion II” could have been a great, dedicated transport for mech/elemental nova formations, which is an even bigger hole in Clan transport than a dropship for vehicles. But instead the Clan Lion got relegated to unarmored infantry, of all things, which is probably the thing Clan toumans least need to move between worlds.
Like I wrote in that old thread, the Clan really need a retconned, dedicated, inter-Clan, binary- or trinary-sized dropship for mech/elemental novas that drop from altitude together. The Outpost is cool and all, but it has limited distribution across Clans and eras and the vehicles and four (?) fighters are odd and unnecessary distractions.
Same goes for a retconned, dedicated, inter-Clan, binary- or trinary-sized vehicle carrier. The Polaris is also cool and all, but its distribution is even more limited than the Outpost, and the elementals and cruise missiles are also odd and unnecessary distractions.