Your stocking plan is very similar to mine

I have a 75 gallon tank that, at the end of stocking, will have a total of: 2 Angels, 10 Harlequin Rasboras, 8 Zebra Danios, 6-7 CHerry Barbs, 3 Rams, and 4-6 Otos.
As for a 90 gallon tank, your plan is perfectly fine, both in terms of fish compatibility and fish numbers. I can see you did your homework well

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My Angels were raised with smaller fish, so they don't bother any of my small fish. If you do the same, your Angels should be OK with smaller fish.
In a 90 gallon tank, you can have schools of small fish like Harlequins in groups of 10's and more. A schooling/shoaling species looks best in a large number. They also feel safer in larger numbers. In fact, a large group of small schooling fish looks stunningly beautiful

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You said you're thinking of: 8-10 cherry barbs, 8-10 harlequin rasboras, 6-8 otocinclus, 6-8 dwarf loaches and 6-8 cories. That's about 60" - 77" of fish (if you count by the rule of "1" of fish per 1 gallon of water" - though this is only a general rule; the body mass must be taken into account as well). Anyway, even with 77" of fish, you're OK in a 90 gallon tank. When you stock, leave some free extra space (i.e. do not stock to the full 90") because gravel and decor/plants take up a lot of space too.