Given your history is of all but 2 years, the likelihood of your credit score dipping (upon adding new cards) because the overall/avg length of credit history dipped is low. Or at least the effect of that can be nullified soon and fast because they all age together and in a few years you'll see a good increase in the age.
The overall utilization may come down but it won't help with any specific card or its balance. And some lenders look at the avg utilization but may also look at if you have maxed out 1 or 2.
If you have a balance and would like to spread even your utilization then make sure you have 0% APR on 1 or 2 new cards and low/no balance transfer fee. (Unlikely this was what you were looking for.)
All that said, you shouldn't get 5 cards at the same time. You could easily achieve something similar with 2 or 3 cards (assuming you have 1 or 2 already). In fact it'd be good to have one of each of Visa, MasterCard, Discover, Amex (Assuming USA).
Also over time, you may evaluate credit card offers and may want to take up some that give you good bonuses and ongoing rewards. Getting 5 at one time now may tie your hands down in the immediate or mid-term future. Lenders don't like to see that kind of spike.