If the act were amended to lower the required number of years from 10 to 3, that would have no impact on other countries. They each have their own acts. To be eligible, you need 25 years in certain cases, and 10 years in others. A minimum is established, and many factors are taken into consideration.
Few countries have an old age security system based on residence. In Australia and New Zealand, however, a minimum of 10 years is applied. The systems of those two countries are similar to Canada's. Most foreign systems are based on contributions, as in the case of the Canada Pension Plan. The number of years required varies from country to country. It's 25 years in Japan, 20 years in Italy and 5 years in Germany, I believe.