I thought that you need different buildings to get the boos, as in, placing two buildings type A will not give you boos, you need ABCDE.
Personaly i will not go for the set at all, too low of a chance. If possible i`ll try to get some premium buildings or SoKs.
Indeed. For that reason I got the second Sakura and as you say the 2 Sakura (placed wisely) get the bonus bcos they are touching 3 different buildings: the Emperor's Entrance, the Gong of Wisdom and the Zen Zone.
Look at the figure of the garden and imagine that instead of the Nishikigoi Pond you place another Sakura
The figure of the Cherry Garden on the announcement shows the 5 different pieces placed correctly but the announcement doesnt mention (or do not make it clear) that you will be able to get more (repeated) pieces and with those extra pieces you can make other combinations or expanding your Cherry Garden giving you different bonus (more FP or less, more attack or less and so on)
Even though you will need some luck I recommend you to build this puzzle. If you manage to get the full Cherry Garden set you'll get (OF stats):
(5 pieces) 1 Sakura Rock (5x5):
5 FP (daily)
5 goods of your current era (daily)
+5% attack boost (permanent)
+5% city defense boost (permanent)
95K supplies (daily
20K coins (daily)
132 medals (daily)
5,600 happiness (permanent)
(5 pieces) 2 Sakura Rock (5x5):
3 FP (daily)
5 goods of your current era (daily)
+10% attack boost (permanent)
95K supplies (daily
20K coins (daily)
66 medals (daily)
2,800 happiness (permanent)
(6 pieces) 2 Sakura Rock + 1 Nishikigoi Pond (5x5 + 6):
3 FP (daily)
5 goods of your current era (daily)
+10% attack boost (permanent)
+2% city defense boost (permanent)
95K supplies (daily
20K coins (daily)
66 medals (daily)
5,600 happiness (permanent)
..not bad for a 5x5 at all.