Yeah, tanks especially do poorly on their own.
this is true consistently. a Lone Tank is an expensive target, not a combat asset. Conventional vehicles are
team players, regardless of the type, getting isolated is BAD.
It used to be
worse for solos. Good tank/conventional players know two basic things:
1. if you're relying on a single unit to fill a critical role, that unit will die early, or be cut from the formation and rendered useless by an alert opponent. Thus, you always want a backup.
2. You're
going to take losses, plan for it, assume it when you're selecting your combat units, some, most, or all of your conventional units WILL be mission-killed at minimum.
even with the added on hit location tables and nerfed Inferno rules to keep them alive, tank play is not like 'mech play, the fundamental assumptions in 'mech play
absolutely do not apply, because you WILL lose units, whereas 'mechs might well make it all the way through a scenario with lots of damage but still alive, tanks will be destroyed. Maybe some, maybe all.
Plan accordingly.
The Ontos is a good 'pinch point holder', that is, like other slow tanks, it's not a maneuver unit and you'll suffer a lot if you try to play it like one. what you want to do, is move it into a spot where approaching sight-lines are restricted, and routes of approach are confined, and park it. Like every other assault class tank, the Ontos doesn't benefit from moving, but under TW rules, it CAN benefit from sitting still and denying or complicating an approach.
especially given the redundancy of the weapons fit. Eight medium Lasers is eight times a laser has to be put out of commission to disarm it, it won't run out of laser ammo, so for that nine hexes, up to forty points of damage per turn is possible.
in five point groups, though you do have to roll a lot of 'to hits'.
This is up there with a Demolisher, except that the Demolisher CAN and if it isn't killed, likely WILL run out of ammo.
The Ontos is, therefore, a "Turret on tracks loaded with lasers." Using it like a quickie bunker is the killer application for it, and with a 3/5 movement curve, the
best use for it given the hit location tables vehicles have, and the penalty to gunnery for flanking (which, in simplest terms can be seen as "If you're flanking you're still more likely to be hit, than you are to actually hitting anything-even if they're stationary")
Something to consider is that units like Alacorns, Morgans, Rhinos, etc. pack a long-range punch... and then tend to struggle a little when someone gets up in their faces. I personally watched an Alacorn (HGR version) get absolutely gobsmacked years ago in a game by a Ghost Bear-owned Koshi that just stayed right next to it, beating on it every turn- when the Alacorn had the initiative advantage, the Koshi simply hopped away out of danger, then hopped back over to keep working on it- made a lot easier when the tank's treads were destroyed. That's not fun for the tankers.
Know what makes fast harassers like a Koshi, or Savannah Masters, or... well, Harassers... think twice about something like bum-rushing stuff like that? A hefty close-range nightmare unit as a bodyguard. Demolisher, Hunchback, ONTOS... I know I'll give it a few before I run in to try to pummel an Archer's rear armor if it means exposing myself to that disco-ball on treads.
That's the thing to remember on the Ontos- like many units, it's not really designed to be a lone gun. It's designed to be part of a unified force- and there, it really starts to shine. (That it's an FWL unit, a faction that relies heavily on inter-linked forces, only reinforces this)
You've just pointed out the killer example of why you don't send tanks out by themselves, and why flanking on a 3/5 is bad for the tank, where it's not such a big deal for a 'mech. (Being hit hurts a lot more on a tank, even if the damage is low...unless you're parked. Being Parked is awesome, most of the incoming damage will hit motive systems you're not even using, or hae to be exhausted against the armor like a fortress wall.)
The first mistake, was taking an Alacorn without...another Alacorn at medium or short range to scrub your back. Tanks with range (Alacorn, etc.) work better in pairs, with maybe two to three hexes separation depending on minimum range. (thus, why you only need "Dedicated bodyguards" in scenarios where you also run 36 designs in a 36 member battalion. Generalists in quantity is how to make 'mech minmaxers pull hair from their heads in frustration.)
aside from the killer application of 'Stationary Obstacle', if you MUST try to maneuver with slow tanks, have your plan figured out before the first initiative, and only make minor adjustments-that is, keep moving. You should still refrain from flanking as much as possible, but move every turn with every thing you can move, and use that movement to apply pressure.