Is it discrimination that federal employees who are also in the national guard are not eligible for TRS?

TRS stands for tricare select reserve. TRS is a premium based insurance that national guard and reserve soldiers can enroll in. However, since my husband was hired by border patrol, he is no longer eligible to enroll in TRS because he became eligible for the federal benefits package. I think this is unfair and discriminatory. If the federal benefits were even comparable to TRS i would understand. However, the federal benefits are a lot more expensive and the deductibles are more than twice as high.