Objective is to maintain (or increase NAV). The yield on that NAV (even after a dividend cut) should then be competitive with other alternatives. One rule to not violate: never pay more than NAV.
If you go back using Valueline on NLY you will see that if you avoid paying a premium that even with a dividend cut within about a year you will about even with the dividend included and longer term you will be profitable.
Note that the strategic objective for AGNC and MTGE is to favor protecting NAV over chasing income.