yes, you are correct in your quotes, and then as your quote from the multiclass section notes, reference the individual classes:
*snip*
in a more philosophical perspective, i can understand your reading, i think it is a far more strict reading (as the entire thing is a bit ambiguous). i would argue that my reading is still in line with balance and power. you still arent going to beat the system, spells are locked in at the same level for everyone in 5e, example - fireball will never be available to any character before their 5th overall level.
so anyway, (SORRY OP, DIDNT MEAN TO HIGHJACK YOUR POST) to bring it back to the original poster, that is why i believe the stacking of martial levels if you will actually works well. maybe count a valorous bard as a half level progression for these purposes (non martials obviously count as 0s). as long as you are hitting the same milestones on when the martials should be getting their second attack, then i dont see the problem.
The multiclass rules reference the individual classes to determine which spells can be known, but it specifically restricts the player from using all the available spell slots from multiclassing. To steal from [MENTION=6784845]MonkeezOnFire[/MENTION] 's post:
"You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class. <SNIP> If you have more than one spellcasting class, this table might give you spell slots of a level that is higher than the spells you know or can prepare. You can use those slots, but only to cast your lower-level spells."
This means that the multiclassing player only use the individual class levels for determining spell availability. It specifically states that that you can have higher level spell slots than you can prepare.
Using [MENTION=6784845]MonkeezOnFire[/MENTION] 's example of the Ranger 4 / Wizard 3, the player assesses which spells a ranger 4 can know instead of which spells a ranger 7 can know. Similarly the player separately assesses which spells a wizard 3 can learn instead of which spells a wizard 7 can learn. If the Ranger 4/ Wizard 3 could prepare the spells of a Ranger 7 and Wizard 7, the second part of the quote would be impossible to attain: "If you have more than one spellcasting class, this table might give you spell slots of a level that is higher than the spells you know or can prepare. You can use those slots, but only to cast your lower-level spells." There would never be spell levels that the PC could not prepare spells for.
This keeps with the spirit of multiclassing in general. Character creation is a set of choices that are in balance with one another. A player who decides to multiclass specifically chooses to trade increased power for increased variety. So the multiclassed fighter loses / delays 1 or more extra attacks, and a multiclassed spell caster loses / delays more powerful spells. The same is true of any multiclassed character as feature, ability score increases, etc. are pushed back from when they could be attained.
I have a Rogue 7 / Monk 1 at my table. If everything goes well, we will actually make it to the end of the adventure path we are playing and make level 20. She will never get Stroke of Luck, and she will probably pick up other levels of monk which means she will never get 10d6 sneak attack dice either. But getting some monk levels fit with the character's back story, and the player wanted to try combining the rogue with unarmored defense. That is the choice the player made, and it is no different than a fifth attack and 9th level spells.