You are right, but thats the point, there is no guaranty that you get the seed that owns a pip or a tree or both. So if you wanna play with pip or trees, you need to check the seed in debug mode, to be sure there are both. And trust me, it takes a while, and only the water planet had a chance...
Can you add in the next patch please, also a higher chance to get forest biomes (pip + arbor) in the classic start? The only way atm is spawn them in. Or if you are lucky and searching the needle in the seeds, you got on the water planet 1.... single....arbor tree...or a pip.