Since it makes zero sense, i consider this a bug:
First the Facts:

Factional Commodities

As far as i can see its always 3 commodities per faction
1x 50 Faction ore  + 30 Plant 1 + 25 HDT
1x 50 Faction ore  + 30 Plant 2 + 25 HDT
1x 50 Faction ore  + 30 Plant 3 + 25 Liquizit

Per Faction there are only growing 2 different plants, which means,
there is always a factional commodity that cannot be refined without importing the plant component.
Thats ok, since it opens up an opportunity for trading even between alpha islands, not only alpha<>beta like it is with epriton.
Each faction related item has at least one of those commodities listed in its component list.
For example:
- Slugs always list a nuimquol component. (polynitrocol)
- Kinetic Hardener lists thelodica component (theledica has best kinetic resists)

Second - the bug:

the always listed factional component is the one that lists the plant that doesn't grow on that factions islands.
Example:
- Polynitrocol contains triandlus

Not only does this result in inability to even build ammo out on a Gamma island,
its also raising the complexity of building anything.

Third - the possible solutions:
(from best, most work,  to worst, least work)

1. review component list to contain less off-faction ores/plants where its not logical
2. change refining tables of all factional commodities to contain only the factional plant
3. change refining table that at least the faction-component in ammo and weapons doesnt need off-island plant