Barbarian Archetype (Savage + Mad Dog) legal?

[Tactical Monkey]

Savage Barbarian: At 7th level, the savage barbarian gains a +1 natural armor bonus to AC when wearing no armor (shields are allowed). This bonus increases by +1 for every three levels beyond 7th.
This ability replaces damage reduction.

Mad Dog: At 10th level, a mad dog gains damage reduction. At 13th level and every 3 barbarian levels thereafter, this damage reduction rises by 1, to a maximum of DR 4/— at 19th level. A mad dog's war beast gains the same damage reduction as the mad dog.

So my question is that since Mad Dog does not in fact state "replaces" or "alters" like most archetypes in how or when you get it, does it mean that...

1) The barbarian at 7th level loses DR for Nat Armor, then at 10th level the barbarian [u]gains[/u] DR for himself and his companion.
2) No the archetype combination is illegal and it simply needs a FAQ to errata a mistake that was made when making the archetype.

As for why the question, I'm brewing up a new barbarian since my previous barbarian got one shotted by a crit.

[Korthis]

I don't think you can combine them because the savage barbarian replaces damage reduction and mad dog changes (delays) it but it is still the same ability. So they can't be combined at all.

[Der Origami Mann]

" (...) A character can take more than one archetype and garner additional alternate class features, but none of the alternate class features can replace or alter the same class feature from the core class as another alternate class feature. (...) "

You can´t take both archetypes, you only can make a houserule for it.