OOC:
We could adjust to get to that position/scenario, but I think it would take an effect.
I had moved Thorn to the point on the map now trying to do something that made sense for
1) the idea of "stepping away from the gel",
2) allowed Attack to MX, and
3) avoided giving OA to SM7.
In order to use Sentinel, it seems that you would have to be adjacent to your ally, but also close enough for a quick strike against the offending opponent. The way I could think of that is to shift Thorn right on top of the body where Myrmidon X lies now. It would be as if Thorn stabbed that guy dead and then stepped right in to overtake his spot. At that point, Thorn would be adjacent to Bryn, but also threatening Myrmidon Y with a hair-trigger Sentinel option, maybe even as soon as this round (R3) depending on if MY Attacks Bryn.
So that would be the main upside. Other upsides might include:
2) cutting down on the possibility of Thorn getting separated and isolated to fight healthy SM7 and SM8 alone
3) would pull PC group closer together as the battlefield continues to unravel into chaos
Downsides I could see though are:
1) Thorn would have to be on the receiving end of a Reaction OA right then during R3 for moving away from SM7
2) SM7 and SM8 could then flood in hard on that space south of Thorn and Bryn, would leave Bryn in a seemingly crowded spot still so close to the Gel with fewer avenues of withdrawal
3) Bryn could easily be exposed to flanking danger, with the likelihood of enemies on both sides (that could happen anyway, depending - but it would seem inevitable if you pulled in high and left)
Let me know if you want to shift Thorn to stand next to Bryn and MY (over the spot where MX lies).
All strategery! Your call. Good question though.
Anyone else, let me know today if you want any last minute PC Movement incorporated on the map. There are some other places to step. Wherever you end up though we have to think it through on effect from surrounding threats, namely OAs from SMs/Ms and potential Movement and spacing of the Gel!