One of the main reasons why battles are being fought like this (old style) is because its difficult to teleport large troops into dense bunker positions, where its better to teleport near them and infilitrate 'tacticaly'. What better way to display team work than to attack gun mounted bunkers!

Im trying to avoid close combat heroic action (like that of previouse marathon styles) and bring it out into the open fresh air (or stank air of the Pfhor prime) since you are an average infantry-man. There will be points where you will be fighting alone and in new places (maby under ground, maby on new planets... maby..).
And you wont be just seeing old uniformed men (re-clothed), there will also be new monster like suprises.. to suprise you!