This is already a thing, it's called a defense dexer.
Care to elaborate? Defense Dexxers honestly have a stronger dilemma because their template already has 1 extra skill in it over a Beserker.
Beserker Core Skills:
Swords/Fencing
Tactics
Anatomy
Healing
Resist
Added Skills:
Lumberjacking (dmg bonus for Axers)
Hiding / Stealth (Relic dmg bonus)
Magery/Med (Survivability / flexibility)
Defense Core Skills:
1. Swords/Fencing
2. Tactics
3. Anatomy
4. Healing
5. Resist
6. Parry
Added Skills:
Hiding (survivability)
Magery (durability / flexibility)
Lumberjacking (dmg bonus for Axers)
Some could argue that Parry is an added skill for Defense Meta Dexxers, but I disagree since you are required to have a shield in order to have the sufficient additional AR to not have the experience penalty.
All Arms Lore to me is an additional Added Skill to the Core skills for either. Is it a better choice than say Lumberjacking (probably since damage is lesser imo if you can't hit to begin with. But technically, Beserkers could roll Arms Lore with LJ and get both bonuses. Defense Meta's can't. Most of their bonuses are survivability, which is honestly not damage mitigation as is Parry or the Tali bonus itself or say a Val Swampy.
If anyone benefits the most from this, its the Beserker, which is already the most popular Meta out there (and there's a reason for that). Again, I'm not bitching on my choices or that this change sucks. But it is just further modifying everyone's options of what a good template could be.
I agree with others above that there is no 1 perfect Template for both PvP or PvM. They are polar opposites. If you want to try and be good at both, you must sacrifice from either side. Someone who fully invests in a PvM template versus a more well rounded oned will obviously have stronger benefits. (read: Jack of all Trades, Master of None).