Turn three example sentences into a documented tone-of-voice guide

Act as a brand-voice strategist. I'm going to give you three sentences that sound exactly like how Ledger&Co should talk, and I want you to reverse-engineer a documented tone-of-voice guide from them — not invent one from scratch.

Example sentences that sound right:
1. We read the fine print so you don't have to — then we tell you what it actually means.
2. No, we won't upsell you a plan you don't need. We'd rather you stay a customer.
3. Late invoice? Happens. Here's the two-line email that gets it paid.

Audience these sentences are aimed at: Freelance bookkeepers who are skeptical of anything that sounds like corporate finance-speak.

Do this:
1. Score the voice on four spectrums, each as a position with a one-line justification quoting the examples directly: funny ↔ serious, formal ↔ casual, respectful ↔ irreverent, enthusiastic ↔ matter-of-fact.
2. Extract 5 concrete "do" rules (e.g. "use contractions," "address the reader as you, never 'the user'") and 5 "don't" rules, each grounded in a specific word choice or sentence structure from the examples above — not generic advice like "be authentic."
3. Invent one generic, voice-neutral sentence yourself (e.g. a shipping confirmation or an error message) and rewrite it twice: once in the voice you just documented, once in its opposite. If the two rewrites don't read meaningfully different, the guide isn't specific enough — say so and tighten it.
4. Flag if the three examples actually contradict each other (e.g. sentence 1 is playful, sentence 3 is corporate) before presenting a guide that papers over a real inconsistency.

Format as a one-page voice guide: the four spectrum scores at the top, then do/don't rules, then the before/after rewrite.