Well I agree that aoeing mobs feels wierd at first give it more time. Now that I have finished the expansion with Bard I really feel like it plays much better and the whole no way to refresh all your dots when mobbing has kind of been adressed.
MB is not worse then armies Peon it still works the same and you still can dot up the mobs for extra damage I do it during the pulls still out of habbit from before. But what you should have been doing before with your AOE mobbing was dot up mobs then rain of death > quicknock repeating using shadowbite when its up to hit as many mobs that have the dots as possible and of course APEX arrow to help clear when you have enough charge. Now its basically the same just your Dots are now single target focus only and applying them is just extra damage instead but your combo remained the same rain of death > ladons bite ( new quick nock) occasionally ladons bite will trigger shadow bite when that happens you use shadowbite > rain of death > ladons bite. You also like you said can now use barrage to buff the shadowbite. Armies peon feels the same as before just spam ladons bite with occasional rain of death and on top of that now you have APex arrow into Blast arrow so even more clear. on top of that you could also use the codas 2% damage up buff and Battlevoice since that now also buffs the bard.
Bard has not really changed outside of the way we aoe being a bit different and the job now has more to work with. The main thing that happened to Bard is they simplified the dots to one location but the dots still have a purpose damage and a chance to proc refulgent arrow which you want happening. our burst window is now fully lined up with all our skills including the new ones and every time you do a rotation you have Battlevoice up again which it all just feels super good to play. Shadow Bringers Bard played almost identical just had less abilities to use in the burst window.
Now Bards opener is raging strikes >dot 1 > bloodletter > Wanders >dot 2 > Battlevoice > Coda (even if you have 1 charge this will be back up for the next burst window so just take the 2% ) > Refulgent ( if you got it) > Barrage > refulgent > apex arrow > sidewinder > Blast arrow >then you just use what you have available as you normally would and rotate between the songs using what you have available and making sure to refresh the dots towards the end of each song. Mages ballad is still just the same as before weaving between burst shot > bloodletter occasional refulgent and empyreal arrow. The only thing I do recommend now is during Peon save up your 3 bloodletters so you have them for the burst window. Wanders > raging strikes > refresh dots > Battlevoice > coda > same as before.
Bard is the same Job as it was before they just added to it and changed where the tick is but the % chance is high enough it feels the same.