Haha, maybe you're right, then it's not a fit, although Saturn is somewhat less dark in some later myths where he remains a god of agriculture and civilization.
I was thinking about how Cronus is over thrown and imprisoned because of his devouring and destructive nature (as the god of time, swallowing his children). Falon'din was said to be vain and destructive, causing a lot of death by starting wars to get more and more followers, etc.
Solas as Cronus I can see maybe, as a god who castrates heaven (by cutting off the mortal world from the fade), and causing death through decay/time (loss of immortality). But Cronus was a Titan.
Considering Cronus is a titan and the titans are the children of Gaia and Uranus - who are the "old gods" - while Cronus children are Zeus, Hera, Poseidon etc. - who are the "new gods" - this sort of makes sense (?!).
Cronus either derives from chronology (but most historians consider this wrong) or kraino, which means the perfector completor (kind of hard to find a fitting english translation). Regarding mythology the whole agricultural part isn't that important. It's more relevant to the rituals. In the written sources, especially Hesiod, the most important characterization of Cronus is that he's the god of the golden age like you said which is a time "before time" or "in between the times". His reign kind of doesn't belong to history or physical time at all.
Cronus has been banished by Zeus (and some sources even claim put so sleep) which ended the golden age.
I'll quote some stuff from wikipedia about the golden age (all the sources I have are in german and translating them would be too much effort)
[Men] lived like gods without sorrow of heart, remote and free from toil and grief: miserable age rested not on them; but with legs and arms never failing they made merry with feasting beyond the reach of all devils. When they died, it was as though they were overcome with sleep, and they had all good things; for the fruitful earth unforced bare them fruit abundantly and without stint. They dwelt in ease and peace.
There are also versions according to which men didn't die during the golden age.
And in roman mythology Saturnus reign is expected to return:
Now the last age by Cumae's Sibyl sung
Has come and gone, and the majestic roll
Of circling centuries begins anew:
Astraea returns,
Returns old Saturn's reign,
With a new breed of men sent down from heaven.
Anyway, I suppose the writers didn't do extensive research of greek and roman mythology when creating Solas but the similarities are striking even though most likely accidental.