i think its better to apply together, i don't see why they should deny you because of that. i know of someone that applied with her family and they got the visa on the first application.
i reapplied on the 19th of October, with 2 dependents. bio metrics not needed, English test not needed, i showed funds above $45 000. hope that helps.
You shouldn't be worried, but if you don't mind traveling without your family then you can apply first. I couldn't possible go a day without my family so we all applied together.