Warrior Ancient and Medieval Rules

I'm putting together a Marian Roman 15mm army and was planning on
having the Numidian ally option. I was also hoping to morph this army
on occasion to a Polybian Roman army. I was thinking in that case,
since I would then have the figures, of maybe using some Spanish
Celtiberian allies (that would normally be used with the Polybians)
with the Marians. With the Polybians (and I think any other list that
contains ancient Spanish) the Scutarrii can be armed with HTW and JLS.
It does not appear that this option is available when the Spanish are
used with the Marians. Is this intentional? Just wondering.

Peter