Leo and Capricorn are both very strong signs. So they come together with this passionate, magnificent dynamism between them. However, they are very different in their strengths. Leo is a fire sign. Fire denotes passion, energy, and a certain magnetic quality, a dynamic quality, a search for what's exciting, what's bigger than life. That sums up what Leo is. Leo wants to be the center of attention, needs the spotlight, is very gregarious and extravagant, and lives life on a larger plain.
Now Capricorn is also an extremely strong sign. It is the sign in the zodiac that's at the top of the zodiac, so it represents achievement. Capricorns take power. It's the sign of utilizing its talents to achieve something incredibly magnificent. But their energies do go in different ways because Leo is all about Leo and Capricorn is all about success.
What happens along the way is that Leo, being extravagant, loves to spend money, loves the good life, as I said. Capricorn begins to feel that this won't do, we don't waste money. We need to have success. We need to keep it in the bank. We need to be practical. Then they begin to argue over social life, earning money, careers that go in different directions, who their friends will be, how will they afford this or do that.
The arguments are basically, although it is about friends and money and career and how they should live, basically it's about control. Leo does not want to be controlled, and Capricorn is a controller.