pension plan fund size affecting risk tolerance

In uppermark it says

“sponsors with large plan liabilities relative to the size of their assets have high risk tolerance.”

Shouldn’t such sponsors have a low risk tolerance because liabilities is bigger than the size of asset?

Not really; if they have a large liability and its long term, they would need to have a high risk tolerance to generate strong returns to pay those liabilities. The length of the term would justify the volatility level.