Yeah that looks right to me. Serving an evil god does not mean you are an Oath Breaker. Usually Oath of Conquest are the default Evil paladins. Oath of Vengeance is usually true neutral or neutral good. The rest of the Oath's are various goods. Its only Oath breakers that are horrible and awkward imo. As a player I'd suggest just choosing Oath of Conquest if you want to be evil.
Evil gods muddled things for awhile but Oath of Conquest fixed that in my opinion.
I can see that, though an Archetype I like is actually a good Oathbreaker (which would have to be in something that is not the Faerun setting) where for whatever reason said character has become disillusioned with their god or the gods in general and have abandoned their title as a Paladin of said god. They could be trying to figure out if they want to serve a different god or be simply a godhater who still wants to do good despite hating the good gods and still hates the evil gods. Alternatively they could be serving a new god as a cleric but the Oathbreaker parts could signify that they still spurned their old god or are being spurned by that old god and thus have some lasting effects.
Err the point of my rambling is that while Evil Deities muddle up how many perceive Oathbreakers, I have always seen them as an archetype that can be flexible even if the MM says, "An oathbreaker is a paladin who breaks their sacred oaths to pursue some dark ambition or serve an evil power. Whatever light burned in the paladin's heart been extinguished. Only darkness remains," because I often times see morality as a little subjective and skewed by perspective at points, and gods can sometimes have some very extreme perspectives that abandon any sense of people being complex with many not evil reasons to do evil acts.
tldr; Even though many see Oathbreakers different from how they were before, I have always seen them a bit more different.
