I'm not exactly sympathetic to the perpetrators here.
It's not like it was a once-off offence, or committed in the heat of the moment.
This was a well-organized, professional scam, with a team of people involved. They had no dubious moral justification - this was a deliberate series of criminal acts, committed to make a profit.
If they had instead executed a well-organized insurance scam for several years, or set up an insider-trading ring which ran for several years, they'd probably get similar sentences. To my mind, this is in the same sort of league. Deliberate, dishonest, consistent criminal behaviour for the sake of profit, and with no moral qualms whatsoever.
Send 'em down.