Sprouto
While true, increasing the size of the shield bubble would have far less unintentional side-effects than reducing the bomber AoE would.
T3 bombers are very widely used, popular units, while the UEF shield upgrade is not a very popular upgrade. Many people don't get the shield field upgrade at all because it might overlap with other shields and end up taking AoE damage. Because of this, the UEF stage one shield upgrade is often preferred.
In my experience, to fix this particular bug, it would be a far safer bet to increase the size of the underused shield bubble, than to tamper with the widely used T3 bombers.