That's a quite laconic and exact way to put it
That's exactly what I was thinking when planning my next party 2 months ago. One ascendant and four tacticians (one multi-classing with priest).
Upkeeped BDD/Unbending/Driving Echoes/and other sugar; plus dedicated flanker/unflaker that can re-trigger Brilliant:
via disengaging/reengaging (with Nomad's Brigandine)
via being flanked by enemies (or using blunderbuss modal) and switching Squid's Grasp back and forth
and in case of boss fights quickly repeat it ~10 times once in 30s; because one resource in 6s, is too slow when there is enough + action speed - recovery time)
By the time I finished planning I felt soo dirty
And no longer felt the motivation to play, because why bother when infinite BDD, or overhealing Unbending makes the party unkillable. You've already won.
And at the same time, I didn't want to take another party, because everything else I was coming up with, was strictly subpar.
That's when I started to think about changes to BDD/SoT/WoD/Unbending/Blade Cascade/etc, and looking for ideas)
Since a balanced solution that would feel good for everyone and is also easy to explain/describe and implement is not that obvious, I think one approach could be by starting with a list of what we want to achieve, keep or change.
For example:
I'd like wizard/druid/priest to benefit a bit less from Brilliant, since the current edge case of getting a rank-9 spellusage versus 1 guile/zeal/discipline is too much.
I'd like it to not be possible to cast more than 4 rank-9 spells in 1 minute. Or even 2..3 per minute on average in the long fight. And at the same time I don't want to be hard limited to just 2-3 of them per combat.
I'd like to keep resource regeneration, since I like using abilities; and don't like watching my characters auto-attacking.
I'd like to have the dilemma of: do I make my party [sturdy but slower] or [faster but more fragile]; instead of [faster but more fragile; and running faster out of resources after which becoming even more fragile]
I'd like upkeeping BDD 24/7 to not be possible;
But at the same time I don't want to limit priests to just 2 BDD casts per combat; I think upkeeping BDD on 2-3 party members for 50% of combat (for medium and hard fights) is a reasonable upper limit
I'd like upkeeping very high defenses 24/7 to not be possible; unless you give up enough acc/dps/penetration.
I'd like upkeeping Unbending 24/7 to not be as effective. Shorts bursts of 15s hard-to-kill once in 30-60s; or limit it's healing to no more than 50-60% of damage taken
I'd like upkeeping Blade Cascade for 24/7 to not be possible, since it kills the point of other stuff that decreases recovery-time; and completely removes the speed downsides of heavy armor
I'd like it to not be possible to keep buffs for over 9000 seconds; since it unbalances the [strong but short] vs [weak but lasting] effects
I'd like martial classes to have some additional, but x2..x3 weaker AND conditional means to regenerate resources. This will decrease the importance of Brilliant for them. Or will bring their regeneration closer to casters', when used with Brilliant in tandem
I'd like resource regeneration to be a little bit faster if you really build for that; or invest in high DEX / action speed
...
Now, what are your likes?