score:5
You are applying to the UK long-term Standard Visitor visa that lasts 2 (or 5 or 10) years.
First, the UKVI Visitor: supporting documents guide is unequivocal:
If you submit a document that is not in English or Welsh, it must be accompanied by a full translation that can be independently verified by the Home Office.
Then, you decide what will show that you meet the requirements of Appendix V: Immigration Rules for Visitors, whether that be a statement from your employer and/or financial documentation.
Electronic bank statements from an online bank account should be accompanied by a bank document on its letterhead, verifying the authenticity of the statements.
Electronic statements from a bank that is not exclusively online, you would want to provide:
➢ electronic bank statements printed at the bank on its official stationary; or
➢ electronic statements you print which have the bank's official stamp on every page; or
➢ a supporting letter from the bank on its letterhead, confirming the statements' authenticity.
In the application itself, Part 4 Your Family, it will be clear that you have a spouse and children, and that they reside with you in Germany. That, along with proof of employment and financial viability are sufficient. You do not need to provide any further documentation, e.g., marriage or birth certificates.
More is not necessarily better: while UK Immigration asks for an applicant to explain why they wish to enter the country, it outlines what supporting evidence may be appropriate, not requisite; you decide what best reinforces your application.