Warhammer 40,000 8th and 9th edition have done a lot for the game, its player base, and its fun level for the majority of the player base. I take all the Warhammer games for what they are; ridiculous dice fests with pretty toys and absurdly fun story to relax and enjoy. People who take the equipment depicted and fantasy politics seriously confuse me.
Do not ever, I repeat, DO NOT EVER argue with me anything about this fine model:
The Invictus Tactical Warsuit model is the epitome, NEY the POSTER CHILD of Warhammer as a hobby. An impractical work of beauty with a machine gun in a holder and a pilot behind some sweet roll bars. If you are seeking logic, please go elsewhere, as logic has been left as an orphan on the doorstep of the Schola Progenium and raised to hate the xenos and purge the heretic. But I digress...
I've been playing a lot of battles recently and one of my favorite units to use is tactical squads because I dig combined arms military tactics. I'm having a mixed bag of results with them though and their versatility may have accidentally been hamstrung to the point that there is effectively only one way to use them.
I think of tactical squads with four applications:
1. the full squad role: Ten models that take and hold a position using their firepower to either draw the enemy, deter the enemy, or shoot at stuff because why not. I'd classify this as the least flexible of the uses of this unit and they are either going to be standing on the field at the end of turn 5 or died on their hill.
2. the combat squad dual role: Effectively splitting the squad into two roles; one focused on holding a position and one on assaulting the enemy. The heavy weapon would go with four bolt guns while the sergeant and assault weapon would aggressively move through the battlefield.
3. the full squad with transport role: The full unit would ride onto the field in a rhino to fill gaps in the plan as needed, take objectives, complete mission actions, or even just draw the enemy away.
4. the combat squad dual role transport role: Basically the defensive combat squad holds a position and the aggressive one mounts up to attack the enemy, the transport giving them greater speed to reach locations they are needed.
..but I believe that now there is only number 3 in the game for best tactical results at this point in the meta. Firstborn forces are so soft, within context to their big brothers, that eliminating a combat squad is not a lot of work. The game has been moved to a very bloody meta, which is fine it isn't a criticism its an observation. But that means that your sweet 1 wound tactical marines are gonna eat it pretty quickly. Ten of them seem to have staying power and enough shooty bits that they make an impact but a five man combat squad seems to vanish the minute your enemy turns their attention to them, and their offensive power is insufficient to make a solid impact unless you are fortunate.
With something like six games under my belt in the new edition with tactical squads I can safely say my deployment will always be with rhino and will not see them broken up unless there is specific gain to it, meaning points towards winning or points towards cool such as a sergeant charging a carnifex because FUCK YEAH!. That is why I play the game after all, winning is cool, sticking a chain saw sword thing into the guts of a tank bug monster with crab claws is waaaaay cooler.
Frankly good ole James Workshop should just sell them packaged with a rhino, I can't imagine a situation that it isn't a better options. The rhino is an affordable transport in relation to the transports for the primaris marines, both real and imaginary currency. Yeah it doesn't come festooned with guns but it comes with enough. You max out an Impulsor you get 4 guns, you max out a rhino you get 2 guns and a single shot super missile. The ratio of cost by points/power rating/DOLLARS is 3 rhinos for 2 Impulsors, it's a fair trade off no matter how you look at it.
So the TL:DR of this article is this: the tactical squad with rhino is how it should always be configured until things change. The cost is amiable, the strategic use is superior to all other options, and the effectiveness is likely above its logistical investment.
All this stands until like October when the firstborn get 2 wounds.
Side Note: There is technically a number 5. above I refuse to utilize: that of filler. It is not uncommon for 5 man bolt gun wielding tactical marines to be used to fill a slot to gain more command points, and at 75 points to fill the slot it was affordable in the Astartes sense. That is not as much a thing in the new edition, but it was in 8th and it was embarrassing to see.