According to current regulations - Ohio Municipal Income Tax is generally imposed on Wages, salaries, and other compensation earned by residents of the municipality and by nonresidents working in the municipality. - http://tax.ohio.gov/divisions/communications/publications/documents/municipal_income_tax_000.pdf
The rate is determined locally. Galion - 2%; Marion - 1.75%. Here are information for each city:
In the case of individuals who are not residents of this municipality, there is imposed under the Ordinance a tax on all income, salaries, qualifying wages, commissions and other compensation earned, and received, and/or accrued (including earnings deposited by the employee into qualified and non-qualified deferred compensation plans), on and after the effective date of the Ordinance for work done or services rendered or performed within this municipality, whether such compensation or remuneration is received or earned directly or through an agent and whether paid in cash or in property. The location of the place from which payment is made or where payment is received is immaterial.
As you will file Marion tax return as a resident - you will be entitled for a credit for taxed paid to another city - see line 7C
Please provide this information to your tax preparer.