No close range infantry
No line infantry with snares
No decent indirect fire
Emplacements are a useless meme
Tommys are useless until you invest heavily into them.
Not to defend Ullumulu but these are not all weaknesses.
UKF has stock trenches on mainlines so you can avoid getting rushed by CQC infantry and fight them off perfectly well from in trenches. They also have MGs with vet 1 extra range in garrison which synergizes with trenches. They also have good grenades on sections.
You don't need line infantry with snares, they have snares on engineers, they have a sniper with stun shot on every vehicle, good AT guns and good anti tank platforms.
Indirect fire is one aspect, but they have a mobile flamer platform (UC) and sniper who also has flares for base arty to clear strong points. Not to mention Pyro Sections with great sight and base arty. Mortar pits are also available though not very good unless they're in your base or at a defensible spot. Mostly the buffed sniper mitigates this.
Emplacements are useless indeed.
Tommies need super early bolster and then medkits and then become really really good and will be excellent after the moving accuract buff with the patch.
Here's the actual faction weaknesses:
No anti-infantry specialist light vehicle that can be rushed like the T70 or Panzer II.
Slow start with early bolster that can struggle to early blobs on your cutoff and can suffer if you don't have the fuel for an AEC when the Panzer II or flame HT hits the field.
UC is very useful early but easily dies in the mid game.
Unupgraded Royal Engineers have bad DPS which sets you back a bit when you buy them in the mid game unless they get the heavy engineer upgrade in the late game.
No stock mobile reinforce point (like a 251) to reinforce on the field.
Only light vehicle requires a side tech to build.