Excellent question Sonia. I'm a big proponent of scalable, so I'm with you here. Since Marketo now allows Programs/Cloning/Tokens yes it is scalable. A few years back, no way. But now, if you build an excellent program, using tokens for all of the texts in landing pages & emails and asset URLs. Then you just clone the great program, replace a few details in the program tokens and move on to the next one.
My last company had 40 assets, each in 6 languages, all in their own programs.