ASIC implementation of X11 would be a bit simpler and a bit less effective (in terms of performance gain over GPU per mm^2 of die space) than implementation of Quark algorithm.
X11 is rather straightforward, there are some caveats inside hash functions, but for well known hashes it would be just concatenation of published implementations.
For Quark algorithm one can implement 9 hashing stages, 3 of them will be paired - e.g. calculate Keccak and JH in parallel, then discard one of results. Or, to save die space, it's possible to implement 6 hashing cores and some dispatching and routing logic around them.
Anyway, the best ASIC protection is small capitalization of altcoins

Blindly chaining hash functions could theoretically lead to increased collision rate.

EDIT:
Exactly. I expect SHA3 GPU miners to be optimized to the same level very soon.