Good morning guys.
Let's say that i build a Life Oracle with WMC Cavalier Order of the Stars.
The channel ability of the oracle says:
"Channel (Su): You can channel positive energy like a cleric, using your oracle level as your effective cleric level when determining the amount of damage healed (or caused to undead) and the DC. You can use this ability a number of times per day equal to 1 + your Charisma modifier."
The 2nd lvl order ability of the cavalier says:
"Calling (Ex)
At 2nd level, the cavalier can make a short prayer as a standard action, filling him with confidence in his abilities. At any point in the next minute, he can receive a competence bonus on an ability check, attack roll, saving throw, or skill check equal to his Charisma modifier. He must declare that he is using this bonus before the roll is made. He can use this ability up to four times per day, once for each type of check or roll. In addition, the cavalier adds 1/2 his cavalier level to any levels of paladin or cleric he might possess for the purposes of determining the effects of channel energy or lay on hands. "
And finally the VMC says:
"Order Ability: At 7th level, he gains the 2nd-level ability of his chosen order, treating his character level as his effective cavalier level."
The question is, does the abilities of the cavalier stack with oracle level when the determining the amount of heal of my channel ability?
For example:
Channel: lvl 20 oracle = lvl 20 cleric
lvl 20 effective cavalier = lvl 10 cleric
Total : 30 effective cleric lvl --> 15d6 channel?
.....
This is one of those areas where the rules don't work well. You are correct by a "Rules As Written" interpretation, but it's a place where the rules don't make sense. Reasonably speaking, you can't be a better cleric/oracle as a multiclassed oracle/cavalier. It's only because VMC has some weird rules interactions that allow this to happen.
Ask you GM how they want to handle this situation. It should add something, but definitely shouldn't progress above what a level 20 cleric could do. But I really don't know what it should add.