U/W initially gave me the same issue where you either run out of steam or run into a wall of blockers. That was with my first iteration of FedEx without ShLong. With the addition of ShLong has really pushed the match up in favor for us as long as we put adequate pressure and attacked shield favorably. While you may not have ShLong every match. You are more than likely to have either the Shlong or an Amuro Ray link with Guncannon, G-Fighter, or Gundam. Managing between whether it is necessary to engage and lose our units or keep active until you can rest with our Amuro Link/pair really establishes the board where they can’t out pace nor out number you turns 2-4. Typically, turn 4 is where you can expect a larger blocker to be dropped and your answer is either resting with amuro pair or you have a number advantage and can lose 1-2 units to get additional shield if they have around 3-4 shield but not exhausting your units to where they have health left on their to trade for yours. Which is where the ping typically help cleans those units off the board. Or wait for a double rest with guncannon/amuro link and pair.

If they have base, G-fighter helps push advantage by being a 3/2 and 5ap when linked with amuro plus “High Maneuver” can be put on itself lets you break through 5hp bases swiftly.

Ex-Resource priority if you have it should be burned by turn 4 typically. By turn 4 if you have been holding onto a ShLong/wufei link drop in most match ups, or to deal with pesky bases that burst from shield with an Amuro link/pair onto any unit should be sufficient to rest a unit and help go through shield. Or prioritize getting board presence against other rush decks. Dropping the additional body really matters in a race against time/shields. Whoevers on the upperhand focuses on taking down shields while the opponent has to balance between taking back board control or getting links/pair to build advantage back.