Don't forget that four level 2 Sentinel Outposts also means obtaining four Outposts, plus four upgrades for them. That's 8 items needed compared to just one.
Fair point and I will conceded that that does mitigate the reduces percent some. However, for the tracks to have any value at all you need at least one end piece or both end pieces to reach max effectiveness. That is a BIG city foot print for a relatively small bonus.
Background:
Sentinel Tower and Olympic Treasury launched Defense for Attacking troops into the game.
Level 10 Olympic Treasury: 10 items, 20 squares, 10-26% bonus (depending on age), 0.5% to 1.3% per square depending on age.
Level 1 Sentinel Outpost: 1 item, 1 square, 2% bonus, 2% per square
Level 2 Sentinel Outpost: 2 items, 1 square, 4% bonus, 4% per square
Example 1:
Lvl 1 Carc, Lvl. Sphen, and one Rous only takes 3 items but 32 squares and only gives get 6% boost while attacking. At 0.187 % per square that is TERRIBLE space use for a fighter.
Example 2:
Lvl. 6 of Carc, Lvl. 1 Sphen, and one Rous takes 8 items and the same 32 squares and gives a sad 14-23% boost while attack. At 0.437% to 0.718% per square that is still does not mach the Treasury let alone the Towers in terms of space use for a fighter.
Example 3:
Lvl. 6 of Carc, Lvl. 1 Sphen, and TEN Rous takes 17 items and the same 68 squares and gives a respectable 68-76% boost while attack. At 1% to 1.117% per square that is still not meeting the Treasury baseline and serious fighters would be better off pursuing Lvl 1 sentinels.
If you upgrade the other side you get benefits but not attack related and it takes even more items to get. It takes 17 items to get close to the Treasury's space efficiency for a fighter and the Treasury only took 10 items. I am not saying this is a BAD building for a fighter if they can get enough Rous Tracks in, but surely is not super exciting. After a series of disappointing event rewards for a fighter trying to maximize their fighting prowess I was seriously hoping for something more inspiring then this. Especially when you add the complexity of the event.
If they increased the defense to attacking troops by just 1% for the Rous track it would dramatically improve the desirability and place it on a more competitive level with the Olympic Treasury.
I apologize for the excessively long post.