Basically, nobody can really tell which is the "right" investment method (save in the bank or invest in stock). So, either of you could be wrong. If you just leave each other alone to make individual investment decision, for a family, it is diversification. Diversification is good, recommended by almost all financial advisers. (And you won't know the real result till 30/40 years later...)
However, there will be problems if you have big difference on how to spend money. For example, one want to borrow tons of money to buy a big house, fancy cars and spend on luxury items regularly; the other one only want to live a moderate life based on income and have rainy day savings. If this is the case, you will have conflicts regularly, which could hurt marriage.
I recommend talking about financial issues before getting married. Have a general idea on how to share the expense on daily life, buying house, raising children (e.g., shall the wife keep working after child is born),... Then, as far as both parties are reasonable/flexible, marriage won't be affected by investment decisions.
Good luck.