The problem is not the number of letters used, but the number of ideas attached to one identifier.
In Greek, Latin, French it's much easier to make compound words already.
Dutch does it a bit too, and German is quite famous for it. People actually make up words on the spot, and other people can easily infer the meaning.
I learned this the hard way while training a natural language "AI". People just do it in their day-to-day use of those languages.
In any case, I don't think you need to make up new morphemes for English, it has too many already from all the languages it's been borrowing from. Drawing from the extant pool would be quite adequate for me!
I'm sure the Urbit people will be by to explain that this is being worked on for Hoon, and email me now and I'll get you set up with a planet.
He meant well.
It would be cool to have a tiny vocab (a la Toki Pona) of say 256 single-syllable morphemes of 1-2 consonants and 1-2 vowels.
SimpleBeanFactoryAwareAspectInstance -> Haplefaesthamon
Of course this is probably appealing to conlangers and language nerds, and horrifying to everyone else.