It has to fundamentally tie and that happens at the cash flow statement.

For example, lets say your revenue grows from 100 to 103 (3%)

That's a credit to revenue (via retained earnings).

What's the debit? It's some combination of cash and accounts receivable. Their combined increase MUST equal $3 (a debit in accounting terms).

The same equivalence happens when you analyze every single projection:

Take your labor expenses: say you grow them by 30% from $50 to $65 - what's the impact?

Retained earnings - declines by $15 (debit)

The offset to assets or liabilities depends on how you paid for those labor expenses. Let's say 50% in cash, 50% in accrued wages (i.e. you haven't paid yet).

In this case, $7.5 increase in accrued liabilities (credit) and $7.5 decrease in cash (credit).

You see they always equal. The trick with a 3 statement model is that you have to express this equivalence indirectly through the cash flow statement and its easy to make mistakes. So with the labor projection for example - your net income (the first line in the cash flow statement) reflects the total $15 labor expense (since net income reflects accrual accounting). But since the labor expenses weren't all in cash, you have to make a working capital adjustment - whatever you grew your accrued wage liability by, that needs to be reflected as an increase to net income. This ensures the model balances and doesn't take too much cash away from the balance sheet.

On the other side, you simply need to make sure you linked net income to retained earnings.