If you are using Turbo Tax Desk Top software then you are correct that the tuition will be aggregated onto the parent with the higher taxable income. Unfortunately the only way to work around this is to create separate individual tax returns for each parent and claim the dependant tuition individually between them. This requires extra attention to spousal information input on each tax return under the "Introduction" section. I will pass along your comments regarding the preference of splitting the tuition claim according to your own personal judgement.
