That's proabbly it, If I remember right I read somewhere that you need higher difficulty levels to get the scented messages in the first place and I was only second lowest for my first play.
I wonder if the next grade, Blackbeard is already enough, don't remember the full post.
Aside from vehicles I had a complete Gnome/Lokk'Naar strike team due to the underground missions, Gnomes are also reliably decent against voodoo (at least it seems like it, the VooDoo school text suggest resistance more about voodo skill than power, but I never had any Gnome fall to Star God trickery regardless), and since I got the Moongose earlier than good Gal armor, they became my main force for a while (Also used them for underwater fights until the end).
As for the skullstrider Moongoose thing:
Well depending on the side, Skullstrider has 60- 80 more armor points, not quite 100 (which is of course still enormous).
Still percentage wise Moongose has a bit more than 50% of the armor value of Skullstrider and takes 40% less plasma damage (assuming that's how resitance works, not sure if it's substracted before or after the armor value). Not gonna do the math, but I don't think you'd need 200 weapon damage to feel a difference.
Also I'm not sure if armor size influences enemy accuracy, if it does it would probably also factor in since Skullstrider is twice as big.
An advantage of the Moongose seems to be that you have to get wounded for more than the 25 bonus health points to actually take real damage, at least my fighters regularly could directly return to combat despite taking damage in the previous battle that day. The Skullstrider of course has the same thing going for it with the 15 health bonus, I just don't notice it as often, since they tend to be not wounded at all or dead (neither armor can take a single Sectopod hit though).
Aside from all that I noticed that the Skullstrider seems to be more easily discernibly superior to Moongose in 0-G space missions in particular.