Is it fair for my company to contribute to health insurance in this way?

My company used to pay 50% of my health insur when I participated in group plan with 2 others. I am the oldest in company of 6 total. One person moved away so only 2 of us on health plan. Too epensive for me, even at 50% so I changed to HSA health insurance plan/high deductible plan (1250 deductible) which is lower price than previous plan. Is it okay that company still pays what they used to pay for my epensive plan, even though it's now more than 50%? What about each year when my plan cost increases? The second employee took out his own HSA/hdhp too, but he is younger and male and company is still paying what they did for his former plan, but it is more than 50%. Should company be epected to increase their contribution each year and if so how to calculate? The two of us took out cheaper plan for us and for company, but we also assumed a high deductible which the previous plan didn't have. How do we figure this out...what is fair.