But not always, as this is still a sandbox game! Take a look at my game from early Beta on Legendary level (55% of the resources compared to Medium level).
Keep in mind that I do not attempt to play historically and got some excellent diplomacy results that prevented me from fighting on 2 or more fronts at the same time.
Meanwhile the other 2 big powers were at war with eachother. So I really got lucky there.
Keep an Eye out for the landings in Italy, Spain, etc and the reappearance of rebel states.
Please mind the low recording quality, ingame is much better of course. Please put playspeed at 0.25 in YouTube if you don't want to miss the small details.
During the movie you will see a period of stability. That's when I'm building the Wall from Game of Thrones.

Video
https://www.youtube.com/watch?v=J-cEZXSRpZg
Before After 1 I go northwest ASAP to cut off our own ally from doing a landgrab there. At this point we are very vulnerable. We know Carthage will attack in a few turns, so we need to be fast to get all the neutral cities.
2. Go as fast as possible and get the neutral cities. Just let them burn and send settlers. Resources are very tight at this point, so only do Civil upgrades to prevent uprisings.
3. This numer is missing. Basically I take the pass towards Gaul and exterminate anything east from it. By this time Carthage will start it's landings. Be prepared!
4. After fending off Carthage for a bit(I invest 0 in fleets) ally with Massilia and take out the Celts.
5. On the eastern front take out the German Tribes for the biggest part(1 town was hiding behind a friendly country which would eventually switch sides and ally with Egypt! )
6. With my eastern border secured with a friendly ally, I went southwest and rampaged towards Carthage.
At this time I was up to about 7 or 8 fully upgraded armies with 1/3 experience. I've had maxed out 20 I guess in the end. And up to 20 Triremes. Nowhere near the amount of units Egypt had! Quality over quantity!
7. Those damn tribes, took me longer then I expected and they rose up twice!
8. Carthage was getting wrecked and sued for peace while I was very friendly at that time with their biggest rival Egypt. They were also at war. I got lucky there and managed to keep both at peace for a while.
9. 10. 11. Pavel advised me to build a wall, since I saw like 80 units building up in the east along my border! So I did.
My units rotated between walls and the healing perk did a good job. I think I killed about 80-100 units there.
After the storm was over I attacked out in 3 directions, and met like 5 units opposition each turn. I had about 15 at that point with full experience, so I could clean up pretty fast.
12. 13. This took a bit longer due to the terrain.
14. 15. It took me quite a while to build up the navy at this point. I knew I needed at least 15 triremes. I don't invest anything till I get that technology.
Also having at least 6 ports spread out is needed to facilitate repairs and fast building. The opponent will build like 3 ships each round!
Most of the landings where at point 15, where I made 2 ports so I could safely land my troops between them.
16. 17. 18. 19. By that time they had another huge army, so the landings were costly. Lost about 20% of my armies and had to quell some uprisings.
20. 21. There was hardly any opposition here. My armies had full speed upgrades, so I ran through this area. Egypt was still at war with Carthage.
22. 23. 24. At the same time I did a landing at 3 islands and took them with a combo of influence and units.
25. 26. I had kept Sparta alive and hostile, to keep the other factions happy with me having at least some enemies. Now their time was up as I didn't need them anymore.
27. 28. 29. 30. Egypt offered absorption, so I moved my armies very fast forward at 29 and 30, and moved fleets with guard armies into position at 27 and 28. Took a gamble that no uprisings would take place at that time.
31. 32. 33. The invasion was swift as Carthage was totally exhausted from the war against Egypt. They did have a huge fleet of 10 triremes, but mine had nearly 100% experience and full upgrades. They didn't last long.
34. As I was about to do the last push they offered absorption.