I don't think any adjustment is necessary. Before expert tactician at L7, the only tactic that is grossly dependent on party composition is Reload!, and Reload! is a trap. Like Tomppa said, the mechanics of classes that actually use reloading weapons rarely line up in a way that makes the tactic useful. It's one of those powers that is fantastic in a vacuum, but just doesn't work that way in real play. And that's assuming you've got a prepared table to use it, which you're obviously not guaranteed here.
There are lots of PF2 powers that aren't as good as they sound on paper, and quite a few that aren't ideal for organized play. Reload! is both, but there's a lot of other choices that do just fine.
I do like the idea of a mid-level commander who brings some spare bucklers or aeon stones to enable Shields Up! (or Mirrored Wall at 15+), though. Dusty rose prisms are 50g, and more non-shield-wielding characters really should consider picking one up, just in case.
Tomppa wrote:
...you can only have an ally benefit from 1 per turn...
I just wanted to note that that's not strictly true for two reasons.
First, remember that Drilled Reactions effectively allows one ally to use a tactic's granted reaction for free. When my playgroup first read this, everyone assumed that was to allow someone to keep their "normal" reaction available for class stuff like Reactive Strike, Shield Block, or assorted champion things. And it can be. But it ALSO means that you can have an ally double-up on tactical effects. I can and have used Pincer Attack (>) to allow the entire party to reposition and inflict off-guard to the enemies, followed up by having a high-damage melee Strike Hard! (>>) to drop a full attack-bonus Strike into one of those off-guard targets prior to their place in initiative.
Second, not all tactics actually burn reactions in the first place. Defensive Retreat is probably the (no pun intended) banner carrier here, although you can also do some things with Coordinating Maneuvers (the Step is a free action; the Reposition is a reaction, but is also optional) or End It! (but I loathe End It!...). With Expert Tactics, there are occasionally reasons to burn Take the High Ground in exactly this way (because it grants a free-action Stride for just one action, it's situationally better than facially similar move-and-optionally-do-something tactics.