Something like this.
Building level --- Min number of catapults needed to take the building down to level 0
16 370
15 317
14 271
13 230
12 195
11 163
10 135
9 111
8 90
7 72
6 56
5 42
4 30
3 20
2 11
1 4
Rams do more damage than cats per unit.
Cats cost more resources and more population to build.
Cats can attack any building other than the hiding place whereas rams can only attack the walls.
Cats have better raw stats (but it's not much when you consider the increased costs).
Level 1 Catapults:
Quote:
30 to 29 -> 20
29 to 28 -> 19
28 to 27 -> 17
27 to 26 -> 16
26 to 25 -> 15
25 to 24 -> 13
24 to 23 -> 12
23 to 22 -> 11
22 to 21 -> 11
21 to 20 -> 10
20 to 19 -> 9
19 to 18 -> 8
18 to 17 -> 8
17 to 16 -> 7
16 to 15 -> 6
15 to 14 -> 6
14 to 13 -> 6
13 to 12 -> 5
12 to 11 -> 5
11 to 10 -> 4
10 to 9 -> 4
9 to 8 -> 4
8 to 7 -> 4
7 to 6 -> 3
6 to 5 -> 3
5 to 4 -> 3
4 to 3 -> 3
3 to 2 -> 2
2 to 1 -> 2
1 to 0 -> 2
Total cats: 238
Level 2 Catapults:
Quote:
30 to 29 -> 16
29 to 28 -> 15
28 to 27 -> 14
27 to 26 -> 13
26 to 25 -> 12
25 to 24 -> 11
24 to 23 -> 10
23 to 22 -> 9
22 to 21 -> 9
21 to 20 -> 8
20 to 19 -> 7
19 to 18 -> 7
18 to 17 -> 6
17 to 16 -> 6
16 to 15 -> 5
15 to 14 -> 5
14 to 13 -> 5
13 to 12 -> 4
12 to 11 -> 4
11 to 10 -> 4
10 to 9 -> 3
9 to 8 -> 3
8 to 7 -> 3
7 to 6 -> 3
6 to 5 -> 3
5 to 4 -> 2
4 to 3 -> 2
3 to 2 -> 2
2 to 1 -> 2
1 to 0 -> 2
Total cats: 195
Level 3 Catapults:
Quote:
30 to 29 -> 15
29 to 28 -> 14
28 to 27 -> 13
27 to 26 -> 12
26 to 25 -> 11
25 to 24 -> 10
24 to 23 -> 9
23 to 22 -> 8
22 to 21 -> 8
21 to 20 -> 7
20 to 19 -> 7
19 to 18 -> 6
18 to 17 -> 6
17 to 16 -> 5
16 to 15 -> 5
15 to 14 -> 4
14 to 13 -> 4
13 to 12 -> 4
12 to 11 -> 4
11 to 10 -> 3
10 to 9 -> 3
9 to 8 -> 3
8 to 7 -> 3
7 to 6 -> 2
6 to 5 -> 2
5 to 4 -> 2
4 to 3 -> 2
3 to 2 -> 2
2 to 1 -> 2
1 to 0 -> 2
Total cats: 178