Well for one, the common playstyles in YR was either tweaked or shunned completely, such as Rhino spam as Soviet (E02 : Accelerant actually made it a point that T1 tank spam in MO is considered amateur move). Turtling playstyles were very much discouraged by making defenses overall weaker. Spamming one type of units will not work in the mod because there are soft and hard counter (or at least that was supposed to be the case until very recent metas), among other things. The maps are also tweaked in that most of them are very much symmetrical and always include at least 1 Oil Derrick near your base.
It is easy to employ a turtling playstyle by building a good base defense consisting of walls of Soviet Battle Bunkers along with Soviet Flak Cannons and then building a few Soviet Wolfhounds to counter any artillery pieces or long-range infantry which may assault your base.
With regards to spamming one kind of unit, that certainly still works with Soviet Wolfhounds. I have used groups of 6 of them to simply destroy enemy bases building-by-building and unit-by-unit. This can easily also apply to Soviet Rhino Tanks.