When we play Epic we very often play on a 9 x 5 feet table. So with two 4 x 4 mats there is a 15 ctms wide free out of limits perimeter to deploy cards, dices...
8 x 4 is enought to play 600 pts games with ease. For 300 pts Epic play sometimes one 4 x 4 mat is enought. If not, two 3 x 3
Perhaps I have played too much cramped minis wargames with too much minis on a too small table. And when whe played hex and counters air warfare games there was plenty of space to maneuver. When exchanged 3 x 3 mats by 4 x 4 feel better.
To my taste this is the smaller game surface needed to play Epic. To deploy Epic ships 3 feet is too short. Turbolasers firing since turn 1.
Do you like big mats?