dHal- root and The Celtic & Germanic Forms

I have question:

How the dHal- root 'blossom, green, sprout' (considered by some dHalh1-
), presents in Greek, Armenian & Albanian,
can fit with Celtic *dol- forms or the Germanic *diljaz forms?

As I know, a supposed a-root cannot have o-grades or nil-grades as
ablauts etc...

In this case should we consider a second root dHel- as Pokorny
supposed?

Even so, is Ok? to have in the same time a dHel- root and a dHal- root?

Semantically all these forms are to close, not to be considered under
the same root.

Phonetically I cannot see how they can fit.

Any feedback?

Marius