Did you find having 5 cities to be easier? I've tried it with 2 and 3 cities and both times, felt it could've been faster. However, I've always had a challenge playing more than 4 cities as Tradition.
It all depends on how good the location of that 5th city is and how soon you get it up.
I usually only build the 5th city if the spot is ideal and i have enough cash to rush buy things like workshop,,granary,watermill,and to buy lux tiles.
some civs can manage this more easily than others.spain if it finds enough wonders,India is great for going wide with tradition